Full face BASIC masks seal around your nose and mouth in the shape of a triangle and are held in place by four point headgear. These masks are used by people who breathe through their mouth during sleep and do not wish to use, or have not had success with, a nasal mask and chinstrap. In general, full face BASIC masks are heavier and bulkier than nasal BASIC masks simply because they cover both the nose and mouth.Size:176±10（L） 115±10(W) 76.5±8(H)