The QuietAir Elbow is designed to fit the AirFit™ F20, AirTouch™ F20, and AirFit™ F30 full face masks.
QuietAir releases the same amount of air per breath as the existing standard CPAP elbow, but it does so gently using smaller, multidirectional openings over a wider area.
Manuals & Guides
My previous one (original one) failed (massive air leakage). Most places don't stock spares (or even have them available for order). Apparently it was the inhale/exhale valve that failed on mine. I don't know how common this is.