AirSense 11 works with all standard CPAP masks with a standard 22mm hose connection. It is not compatible with masks designed specifically for the AirMini. Choose the mask type (full face, nasal, nasal pillows, etc.) based on your breathing style and comfort needs.

You'll want to choose a full face mask that delivers air through your nose and mouth.

If you're new to CPAP therapy or struggling to get used to your CPAP mask, we suggest trying the AirFit F40, which features a low-profile under-the-nose design with a secure seal.

Those who require higher pressure therapy may want to go with the AirFit F20, which has a traditional over-the-nose design that's been proven to fit over 97% of customers.

If you can breathe through your nose, we suggest trying a nasal pillow or nasal cradle mask, like the AirFit P10 or N30. These masks offer minimal facial footprints with a compact design that won't get in the way when you lay your head against a pillow.

Customers who breathe through their mouth should look for an under-the-nose full face mask like the AirFit F40, which also features a low-profile fit with a compact cushion that stays sealed in any sleeping position.

Active side sleepers will appreciate ResMed's AirFit 30i line. Each of these masks has the same minimal footprints and compact designs as other masks we've mentioned above, but with a full swivel hose connection that sits at the top of the head to eliminate hose tangling and mask pulling. Look for the AirFit F30i, AirFit N30i, and AirFit P30i.

Our mask sizing guides can be found on their product pages under the tab "Product guides". Each guide can be printed out and used to measure against your facial features.

When possible, we suggest ordering a Fit Pack, which comes with multiple cushion sizes so you can find your perfect fit every time. If you have to over-tighten your mask to keep a secure seal or you're experiencing air leaks or irritation, try another size.

And remember, if your mask doesn't fit right or you don't love it, you can return it for a refund, and we'll help you find a better one with our 60-Night Mask Fit Guarantee.

Preventing mask leaks:

Proper mask maintenance is the best way to prevent air leaks. Make sure your mask cushion and frame are wiped daily and that the entire mask is hand-washed weekly. And replace your mask cushion at least every 1-3 months.

To test for mask leaks on your AirSense 11:

• Set your cushion in place
• Adjust your mask's top straps
• Then adjust the bottom straps
• Run the Mask Fit check on your AirSense 11
• Make more small adjustments to the fit as needed

What to do next if leaks continue:

If you still can't stop the air leaks, try another cushion size if you ordered a fit pack, or consider ordering a mask liner. If you need help, give our team a call at 1-800-356-5221 to request a return or exchange through our 60-Night Mask Fit Guarantee.