Replacement gel cushion (Large) and SST flap that fits on the ComfortGel and ComfortGel Blue Nasal Masks. Cushion conforms around nose and uses the SST flap, which creates a consistent seal.The Respironics Chin Strap is a basic chinstrap that closes with Velcro and attaches to the headgear straps of the mask. It’s lightweight and easy to use. The chin cradle of the Respironics Chinstrap White has a narrow section and a wider section. You can position the chinstrap either way. Whichever gives you the best fit.If you are a mouth breather, or if you wake up with a very dry mouth, a chin strap can help. Part #302175. CPAP America is your one-stop-shop for all of your sleep apnea needs!