Replacement Headgear for the Forma Full Face Mask. F&P Forma sleep mask forms a superior seal and provides even more comfort with a greater range of movement through the active contouring of its new FlexiFoam Cushion. The T-Piece adds stability to the stylized Mask Base, and works in harmony with the highly contoured Silicone Seal and Under-Chin Design to enhance sleep performance. With its ease of use and superior conforming seal, the Forma sets a whole new standard.