The Headgear Clips are used to attach the lower headgear straps to the full-face cushion if you are using full face Mask. If you are using Nasal Cushion Mask, the headgear clips connect the lower headgear straps to the bottom of the mask frame. One pair of clips are included in each package. Compatibly Information: These Magnetic Headgear Clips are compatible with all N20, F20, F30 & F30i Series Masks.