Thanks to an innovative design, you can now reduce the noise level produced by your Respironics M Series CPAP Machine by as much as three decibels. The device fits onto your existing Air Intake Port and over the filters. Here's a summary of the amount of noise reduction you can expect from various pressures:
If a Whisper Cap is used on an M Series machine without a heated humidifier, it will not fit if used together with an outlet bacteria filter. If you wish to use both a Whisper Cap and a outlet bacteria filter without a heated humidifier, then you should add a Hose Quick Connect or a M Series Tubing Swivel between the cpap machine and the outlet bacteria filter.