We designed this Pad A Cheek Anti-Leak Strap specifically for the ResMed AirFit F20, AirTouch F20, and AirFit F30 full face masks. It adds gentle, even stability over your mask to help reduce leaks, without making you overtighten your headgear. The soft microfiber strap attaches over the hose connection, wraps around your head, and closes with velcro on the side. There are two pieces of velcro at one end, so you can cut between them to shorten the strap if you need to. A covered central velcro strip lets you attach it to your headgear if you prefer. Not sure if a strap will fix your leak? Try this quick test: Loosen your mask straps until the mask leaks. Press the mask toward your face with the palm of your hand against the hose connection. If that stops the leak, this strap will help. Do not use it on a mask where it could cover the vent holes near the hose connection. This strap fits these masks only: ResMed AirFit F20, ResMed AirTouch F20, and ResMed AirFit F30. If you use a different full face mask, see our standard CPAP Anti-Leak Strap instead. For care, hand wash it in warm soapy water and rinse well. You can machine wash and dry on delicate and cool settings. Pink microfiber should be washed before first use to remove excess dye, which is harmless to your mask.