Dear Customer: no longer supports Internet Explorer 6 or 7. These browsers have known security flaws and may not display all features of this and other websites. Learn how to update your browser. You can contact us directly at 1-800-356-5221 to place an order or learn more about our products.

    PR System One REMstar Auto CPAP Machine with A-Flex

    PR System One REMstar Auto CPAP Machine with A-Flex

    The PR Auto CPAP Machine with A-Flex is an intelligent solution that knows when, why, and how changes should occur to consistently and effectively provide optimum sleep therapy. New System One technologies like Humidity Control with Dry Box and Resistance Control for use with any mask, all are helping users achieve effective therapy.

    NOTE: the Heated Humidifier is included in the price of this machine.

    Manufactured by Philips Respironics.

    The PR Auto CPAP Machine with A-Flex is an intelligent solution that knows when, why, and how changes should occur to consistently and effectively provide optimum sleep therapy. New System One technologies like Humidity Control with Dry Box and Resistance Control for use with any mask, all are helping users achieve effective therapy.

    NOTE: the Heated Humidifier is included in the price of this machine.

    Product Features

    The PR Auto with A-Flex includes a carrying case, travel bag, memory card, manuals and now comes packaged with the Respironics Performance Tubing.

    System One Humidity Control

    The PR CPAP humidifier and water chamber design are breakthroughs for managing rain-out and water damage. System One Humidity Control technology analyzes ambient temperature and patient airflow to reach relative humidity at the mask. Choose from 5 levels of relative humidity.

    System One is the first humidifier in the industry which accounts for room humidity. Sensors inside and outside the CPAP machine closely monitor changes in humidity and prevents condensation from forming inside the tube.

    Dry Box technology is another breakthrough in reducing water damage to the CPAP. Several unique designs are incorporated into the humidifier to prevent water from exiting the chamber. To start, the air outlet port has been moved from the side of the humidifier onto the top. This centers the entire delivery; minimizing the total water displacement around the hole. The water chamber is outfitted with one-way valve, between the machine and the humidifier. Any water that manages to escape the chamber gets trapped within the Dry Box, which acts as a reservoir for any water ingress past the valve.

    System One and Dry Box Technology make it possible for the PR CPAP machines to be truly spill-free. This humidifier, even with a chamber filled to the "Full" indicator line, can be tilted, shaken, and even turned upside down without water leaking back into the device.

    System One Resistance Control

    Respironics wanted a machine to achieve optimal pressure no matter which mask is used. Resistance Control is the solution, a numbering system on all of Respironics CPAP masks based on variable resistance characteristics. Each number instructs the device to compensate for different mask types. The result? A consistent and reliable pressure enhanced with all the benefits of Flex Technology no matter which mask is used.

    Advanced Event Detection

    The PR Auto CPAP is designed to identify symptoms beyond classic OSA parameters such AHI, flow limitation, Hypopnea, Obstructive and Central Apnea. With the PR system, detection is expand to include data on Snoring, Periodic Breathing and Respiratory Effort-Related Arousals (RERAs).

    RERAs differ from a Hypopnea event in that a RERA shows increasing respiratory effort with each breath, culminating in a shift in brain wave activity and not necessarily a result of obstruction. Periodic breathing conditions such as Cheyne-Stokes respiration and central apneas are distinguishable from obstructed apnea or snoring events.

    Flex Family Technology

    Flex Technology is designed to enhance traditional CPAP therapy; maintaining effective therapy at minimal pressures. Users new to CPAP equipment find the Flex feature provides airflow at just the right pressure relief for every breath and makes adapting to CPAP therapy easier. The PR Auto comes with both C-Flex and A-Flex modes as well as the new C-Flex Plus technology.

    C-Flex offers a comfortable way to deliver sleep therapy by giving pressure relief at exhalation. Pressure is lowered based on a breath-per-breath analysis and provides up to 3 levels of relief based on the patient's expiratory flow.

    C-Flex Plus is a new enhancement added to PR Pro and Auto CPAP machines. Similar to C-Flex, the technology provides pressure relief during exhalation based on expiratory flow. C-Flex+ minimizes the pressure transition and provides additional comfort when in fixed-CPAP mode. In addition, C-Flex+ softens the breathing cycle between inhalation to exhalation.

    A-Flex is a comfort feature built on top of the REMstar Auto algorithm. If breathing events occur, the algorithm raises the A-Flex pressure profile to eliminate breathing events, while simultaneously making sure that pressure never rises to a level that's unnecessarily or uncomfortably high.

    Encore Data Management and Reporting

    On-board memory has been added to the CPAP as well as storing information on a generic SD Memory card and reads through any SD card reader. Use EncoreViewer Software to monitor therapy effectiveness through a series of reports. A new Patient Flow and Event report enables users to view a weekly breakdown on per-breath basis. Patient data is used to identify particular conditions and events with specific colors.

    Another PR System One Machine Option

    Interested in a system that includes a heated hose? The PR System One REMStar 60 Series Auto CPAP with Heated Humidifier and Heated Tube comes with the same great features as the System One Auto featured on this page. However, the 60 Series Auto also offers an updated humidifier and adds a heated hose to the system to provide optimum humidification for comfort and effective therapy.

    Return On Warranty Issues Only


    This Product Includes...

    Product Specifications

    Pressure Range 4 to 20 cm H2O (.5 increments)

    Ramp Time 0 to 45 min. (5-min. increments)

    Starting Ramp Pressure 4 to CPAP; user adjustable

    Dimensions 7" L x 5.5" W x 4" H, 18 cm L x 14 cm W x 10 cm H

    Weight 3 lbs / 1.36kg

    Altitude Compensation Automatic - Maximum height 7500 feet.

    Filters Pollen and optional ultra-fine

    Device Set-Up LCD/Control Wheel or Encore Software

    Data Storage Capacity

    • Display: Compliance, AHI, Leak, Pressure 7-Day and 30-Day averages
    • SD Card >1 year (daily details with flow waveforms)
    • On-board: up to 6 months

    Compliance Meter Breathing detection

    Electrical Requirements 100 - 240 VAC, 50/60 Hz, 12volt DC

    European Voltage Usage: Yes, outlet adapters required

    Max Exposure Heat for Machine Machine should not be exposed to heat greater than 140 degrees Fahrenheit

    Required Settings: This machine does not have required settings.

    Unless directed otherwise, will leave this machine at its default settings of:

    • Pressure Range: 4-20 cm H2O
    • C-flex: 2
    • Auto On: On
    • Auto Off: Off always offers these services:

    • 8 am to 10 pm CST Toll Free Phone and Email Support
    • 24 hour access to our Support Forum
    • Learning Center for information on sleep apnea and cpap equipment
    • Consumer Purchasing Trends Reports
    • Warranty Services for all items purchased through
    • Insurance Compliant Invoices
    • Free Prescription Request System

    Manufacturer Note

    • A valid prescription is required for the purchase of this product.
    • Philips Respironics products are for sale only to patients within the U.S. and not to other third parties or businesses.
    • All services provided by, including advertisement, ordering, sale, delivery, instruction, and setup of the products are performed solely by and independently of the manufacturer.

    Important Tips

    Respironics listened to the CPAP community and removed the "blue light" LED. The PR was placed in a dark room and the new power light could barely be seen. No more insomnia from excess system lights. The only common parts shared with the M series is the Power Supply. The PR system comes with a separate, external power brick and allows the overall CPAP to stay compact.

    Manufacturer Warranty
    This machine comes with a 2 Year Manufacturer Warranty. will work with the manufacturer on your behalf if the machine needs repairs. Please follow these steps:

    • Contact us at or 1-800-356-5221 to receive an RMA (Return Merchandise Authorization) Number before returning the equipment
    • Include a note with the machine describing the issue you are experiencing, along with your full contact information to include a return shipping address and the RMA number provided to you
    • Ship only the defective items to at 13235 N Promenade Blvd Stafford, TX 77477
    • Do not return accessory items such as the carry bag, hose or power cords
    • Loaner Machines are available for rental during the warranty process
    • Email updates will be sent to keep you informed as the machine moves through the warranty process
    • will contact the manufacturer on your behalf and handle all shipping between us and the manufacturer
    • The repaired or replaced unit will be returned to you. Shipping charges may apply.

    Please note: The manufacturer warranty is voided by water damage or misuse of the machine.

    Humidifier Modes PR System One Heated Humidifiers Version 1.22 or higher have two modes:

    • Classic
    • System One Humidification

    NOTE: The version of software installed on a machine is displayed on the screen when the unit is plugged into an outlet. The Humidification settings are displayed only when a PR System One Heated Humidifier is attached to the machine.

    Classic Mode
    The CPAP user who wants to control the heat setting on the humidifier should select "Classic" mode settings C1,C2, C3, C4 or C5. The "C" in front of the humidification setting indicates "Classic". This allows you to set the level of humidification.

    System One Humidification Mode
    The CPAP User who wants to allow the technology of the System One Humidification to set the level of humidification delivered based on the humidity present in the room air should select "System One Humidification". The humidification setting will show 1 - 5 but WITHOUT a "C" preceding the number.

    Heating Off
    If set to zero “0”, the humidifier will act as a Passover Humidifier.

    Accessing Humidification Settings:

    1. Humidifier must be attached to the machine
    2. Access the Set Up menu
    3. Scroll down the menu offerings to locate: "System One Humidification"
    4. If set to "On", the technology will set the amount of humidification delivered to the system based on the setting of 1 -5 with 1 being the least and 5 being the most
    5. If set to "Off", the user controls the heat setting based on C1-C5 with C1 being the lowest heat and C5 being the highest heat.

    CPAP Power Options

    Universal Power

    This system operates automatically between 110v and 240v AC. When traveling either inside or outside the USA, there are no switches to switch or fuses to change. The machine will automatically sense what voltage is needed and set itself to run on that power.

    The user will need to adapt the plug that goes into the wall to fit the style of outlet socket that is being used. This is simply done with a Power Adapter Plug kit. This is the same type of plug adapter that would be used with a hair dryer or an electric shaver. World Traveler Power Adapter Plugs.

    Universal 12 Volt DC Power Cord

    This machine come equipped with a DC plug on the back of the unit. This allows the user to connect the CPAP to an external DC battery source. The machine can be powered by plugging the 12volt DC Power Cord into a cigarette lighter plug. This is ideal for traveling by car, boat, or recreational vehicle that is equipped with a cigarette lighter plug.

    C-100 Travel Battery Pack for CPAP Machines

    Weighing in at only 1.16 pounds the C-100 Battery is a terrific option for travel. Plus, the C-100 comes with a DC cable and connector peg suitable for use with the PR System One REMstar Auto CPAP Machine with A-Flex so no need to purchase a separate DC cable. This lithium ion battery meets UN Manual Test and Criteria requirements for travel. The C-100 Pack includes many accessories and a handy carry case designed to allow the the cords to be attached with the battery inside the case.

    Respironics Battery Kit with Universal 12 Volt DC Cable

    This portable battery pack is an external lead acid battery that is the ultimate in power, portability and convenience. This battery kit comes with the Respironics battery and the 12 Volt DC Power Cord (connects CPAP to cigarette lighter socket).

    CPAP Video & FAQ

    Frequently Asked Questions (FAQs)

    What does CPAP therapy do?
    CPAP therapy provides a constant airflow which holds the airway open so that uninterrupted breathing is maintained during sleep. It is traditionally provided through a nasal mask that seals around the nose to maintain the pressure level.
    Why might I prefer an APAP machine?
    Some CPAP users find it more pleasant to breathe with an APAP than with CPAP. The pressure delivered by an APAP machine automatically changes as needed to deliver the minimal pressure required to maintain the airway. The pressure delivered by a CPAP machine is set to a single pressure, the highest necessary to keep the airway open as determined during the sleep study. This is the case even when the higher pressure is needed only a fraction of the time.
    How do I choose the machine that is right for me?
    We provide our customers with many tools to make informed decisions about their machine purchases. Options include:
    • Calling a CPAP Expert Toll Free. 800.356.5221.

    • Comparison Charts. These charts compare available machines, feature by feature. If you don't know the meaning of a feature, click on the question mark for a definition. Click on the image or name of the product for more detailed product information, pictures and resources.

      CPAP Comparison Chart

      APAP Comparison Chart

      BiPAP Comparison Chart

    • Help Me Choose Guide. We created a guide to help you select the right machine according to your preferences. The guide asks you a series of questions regarding your preferences and your prescription. Based on your answers we provide you with a comparison chart of the machines that meet your criteria. Get started here:

      Help Me Choose - Machine

    • Browse Our Machine Product Categories. These categories show each machine our company offers, ranked by popularity. Popularity is determined by a mix of sales data and our in house opinion of the quality of the machine based on our experience and customer feedback. The best products float to the top of our categories.

      CPAP Machine Category

      APAP (Auto Adjusting) Machine Category

      BiPAP (Two Pressure) Machine Category
    How can I compare different machines?
    We work very hard to provide many different ways for our customers to compare products. Here are the machine product guides we have created and maintain:
    • CPAP Machine Comparison Guide. This guide stacks up every CPAP machine we sell, feature by feature. If you don't know the meaning of a feature, click the question mark for a definition. The links below will take you to the most popular CPAPs, or all CPAP machines we sell.

      Compare Most Popular CPAP Machines

      Compare All CPAP Machines

    • Auto Adjusting Machine (APAP) Comparison Guide. This guide stacks up every APAP machine we sell, feature by feature. If you don't know the meaning of a feature, click the question mark for a definition. The links below will take you to the most popular APAPs, or all APAP machines we sell.

      Compare Most Popular APAP Machines

      Compare All APAP Machines

    • BiPAP, VPAP and BiLevel Comparison Guide. This guide stacks up every BiPAP machine we sell, feature by feature. If you don't know the meaning of a feature, click the question mark for a definition. The links below will take you to the most popular BiPAPs, or all BiPAP machines we sell.

      Compare Most Popular BiPAP Machines

      Compare All BiPAP Machines
    What comes with my machine?
    Machines come with a six foot hose, power cord, at least one filter, and manuals. Most manufacturers include a carrying case which is designed specifically for their equipment. CPAP, APAP, and BiPAP machines do not come with a delivery system or mask. CPAP masks must be purchased separately.

    To see the list of what specifically comes with each machine, you can Browse for a machine. Then on the product page, click the "Specs" tab to see a full list of what comes with the machine.

    Which CPAP masks work on which machines?
    All CPAP masks work with all CPAP, APAP, and BiPAP machines.
    Are prescriptions required for mask, machine and/or humidifier purchases?
    Yes. Federal law requires we have a valid prescription on file before we ship your mask, machine and/or humidifier.

    We provide many easy ways to get your prescription:
    • We can request your prescription for you! When you checkout, just let us know you would like us to request your prescription, or you can log into your account to have us request your prescription.
    • Fax your prescription to our toll free fax number: 866.353.2727, or our international fax number: 713.541.7370
    • Email your prescription to
    • Upload your prescription in your account, under the Prescriptions Section
    For more information on prescriptions, please see our Prescription Section of the Learning Center.
    What does an APAP prescription need to say?
    An APAP prescription must contain all of the following information:
    • One of the following words or phrases: "APAP", "AutoPAP", "AutoSet", "Auto CPAP", "Auto Adjusting CPAP", "Self Adjusting CPAP", "CPAP" or "Continuous Positive Airway Pressure" or similar term.
    • Your physician's contact information
    • Your physician's signature
    • The patient's full name

    An APAP prescription may contain the following information:

    • Your pressure range (Optional, Not Required)
      • Example: 4-20 CM/H20
      • Example: 4-20
      • Example: 6-18 CM/H2O
      • Example: 6-18

    CPAP prescriptions are accepted for Auto Adjusting (APAP) machines.
    What is ramp?
    The ramp button on a machine is a feature that allows for a gradual pressure build-up to your prescribed pressure. The feature is enjoyed by those with high pressures because it eases up to their pressure.
    What is exhalation relief?
    Exhalation relief is a comfort feature which reduces the air flow at the time of exhalation, making the breathing process more natural. Philips Respironics and ResMed are the two manufacturers who offer exhalation relief features.
    • Philips Respironics = C-Flex, C-Flex+, A-Flex and Bi-Flex
    • Resmed = EPR (Expiratory Pressure Relief)
    What maintenance is required on machines?
    The only care a CPAP or BiPAP machine requires is to clean or change the filters at the air intake. This keeps the internal parts from accumulating dust. Fine paper filters should be changed out every 30 days, or when they appear soiled. Foam washable filters should be rinsed with clear running water once a week, allowed to air dry, and reinserted.

    Here are some other suggested actions to care for your machine:
    • Keep the area around your machine clean by removing any dust from the area to improve the air quality delivered to your machine and to you.
    • Keep the air intake of the machine unblocked. Curtains, bedding, and papers can easily block the air intake of your machine, reducing the airflow.
    • If a humidifier is used with your therapy, do not pick up the machine with the humidifier attached. With most machines it is easy to spill water from the humidifier chamber into the machine causing damage. Manufacturer warranties are voided by water damage to the machine. To avoid this, remove the chamber from the humidifier and then remove the humidifier from the machine rather than transporting them together.
    • If a humidifier is used, empty the water from the chamber every morning. Accidents happen. If a family pet or family member moves the machine and humidifier with water in the chamber it is more likely that water could be spilled into your machine. Water damage to a machine voids the manufacturer warranty.
    What data capable machines are available?
    CPAP machines which record full data (such as AHI and leak info):

    AutoPAP ("Autotitrating CPAP" or "APAP") machines which record full data:

    BiLevel ("BiPAP") machines which record full data:

    CPAP Machines that only record compliance data (hours used) are:

    What are the CPAP, BiPAP and Sleep Apnea related HCPCS, CPT or billing codes?
    • A7034 is Nasal Mask
    • A7034 is Nasal Pillow Mask
    • A7030 is Full Face Mask
    • A7027 is Hybrid Mask
    • A7044 is Oral Interface Mask (Oracle)
    • A7035 is Headgear for Mask - Any Style
    • A7036 is Chinstrap - Any Style
    • A7032 is Replacement Nasal Mask Cushion
    • A7033 is Replacement Nasal pillows
    • A7031 is Replacement Full Face Mask Cushion
    • A7028 is Replacement Hybrid Mask Cushion
    • A7029 is Replacement Hybrid Mask Nasal Pillow
    • A7046 is Replacement Humidifier Chamber
    • A7037 is Tubing / Hose - Long & Short Tubes
    • A4604 is Heated Tubing
    • A7038 is Disposable Filter (White / Paper)
    • A7039 is Washable Filter (Gross Particle / Foam/ Black)
    • E0601 NU is CPAP Purchase
    • E0601 NU is APAP Purchase
    • E0470 NU is BiPAP Purchase
    • E0470 NU is BiPAP Auto Purchase
    • E0471 NU is BiPAP ST Purchase
    • E0471 NU is BiPAP Auto SV Purchase
    • E0562 NU is Heated CPAP Humidifier
    • E0561 NU is Passover or Cool CPAP Humidifier
    • E0601 RR is CPAP Rental
    • E0601 NU is APAP Rental
    • E0470 RR is BiPAP Rental
    • E0470 RR is BiPAP Auto Rental
    • E0471 RR is BiPAP ST Rental
    • E0471 RR is BiPAP Auto SV Rental

    E1399 is Miscellaneous and is used for other CPAP items.
    Do all CPAPs use filters?
    Yes, all CPAPs use at least one filter that is usually a type of foam material and washable. Some CPAPs offer finer filtration with the addition of a disposable paper filter.

    Cleaning and changing filters is the only maintenance required for a CPAP machine.

    The filters are located at the back of the machine at the air intake. The image below shows the black foam filter at the back of the Everest 3 CPAP Machine.

    How do I change the pressure setting of my machine?
    When a physician orders a pressure change, or a patient moves to an area with a very different altitude and does not have an altitude compensating machine, there are a number of ways to ensure you are receiving CPAP therapy at the correct pressure.

    Sleep laboratories and sleep disorder centers may be willing to make this pressure change. Just call a local hospital or ask your physician to recommend a sleep lab. Be sure to take your prescription.

    A second way is to do it yourself. We sell manometers that are very portable, accurate, and simple to use. All the machines we sell come with instructions on how to set pressure to physician orders. Most patients have little trouble doing this themselves. If you need help we can talk you through the procedure. Contact us by phone at 1-800-356-5221.

    Gauge Manometer (for pressure measurements)

    Fisher and Paykel Water Column CPAP Manometer with HC325 Chamber

    A third option is to ship the machine to us with the new prescription. We will set it and ship it back.

    It is the law and good common sense to run all sleep disorder devices at the prescribed pressure. If you think your prescribed pressure is wrong, talk to your physician.
    How do I use a battery to operate my CPAP?
    All machines can connect to DC power. Some machines are configured to operate on DC Power and have a DC power outlet. Other machines require AC power and will need an Inverter that turns DC power to AC power.

    Having the proper equipment is the biggest key to successfully operating the machine from a battery. For example, if your machine does have a DC outlet and you want to run your machine from a marine battery, be sure to get the correct DC cable for the machine, as well as an adapter cable with alligator clips that fits over the cigarette lighter plug. sells complete battery kits with everything you need for many machines including the correct cables for those machines and batteries. You can see if there is a battery kit available for your machine Here. If you have questions about the specific power needs of your machine, review the 'Power' tab found on the machine's product page, or give us a call at 1-800-356-5221.
    How do I prepare for power outages with CPAP?
    There are a lot of back up battery choices out there that can give you peace of mind in case of a power outage. The Transcend Travel CPAP Machine has Battery Options available that can set up as a fail-over, back up battery. Review the 'Power' Tab on the machine page. sells Battery Packs to accompany your machine if an integrated battery is not available. Visit CPAPtalk for more advice specific to your needs, or view this past thread on the topic here.
    What is C-Flex?
    C-Flex is a pressure relief feature that makes breathing back against CPAP pressure easier to do by reducing the pressure at the beginning of exhalation and returning to therapeutic pressure just before inhalation. Independent studies conducted by leading universities indicate that patient comfort, and therefore, patient CPAP compliance, is higher with machines that use C-Flex. C-Flex is a technology invented by Respironics, is proprietary, and is not available on other brands of CPAP machines.

    C-Flex Easy Breathing Technology Visual Graph C-Flex Easy Breathing Technology Visual Graph

    C-Flex vs. Traditional CPAP: Brown University Study Interview, C-Flex in the Remstar Pro and Remstar Auto
    What is C-Flex+?
    C-Flex+ is an improved pressure relief technology over the previous C-Flex technology. Like C-Flex, C-Flex+ reduces the pressure at the beginning of exhalation. Like A-Flex, C-Flex+ softens the pressure transition from inhalation to exhalation to provide additional comfort in fixed-CPAP mode.

    C-Flex+ Easy Breathing Technology Visual Graph C-Flex+ Easy Breathing Technology Visual Graph
    What is A-Flex?
    A-Flex is a form of exhalation relief which helps the air pressure from an APAP machine mirror a person's breathing. Like C-Flex, A-Flex provides flow-based pressure relief at the beginning of exhalation. Like Bi-Flex, A-Flex softens the pressure transition from inhalation to exhalation to provide additional comfort in an auto-CPAP mode.

    A-Flex Easy Breathing Technology Visual Graph A-Flex Easy Breathing Technology Visual Graph
    What is the difference between C-Flex and A-flex?
    C-flex drops the pressure on exhale only. A-flex drops the pressure on the exhale but also helps with the transition from inhale to exhale.
    Visit the Learning Center