The Blue Eye mask contains a nasal water purge system. This helps to disperse water that has entered the mask. The mask comes with either a silicone or rubber skirt and strap, hard plastic frame with aluminum wrap, single clear tempered glass. Great mask for shallow water and tropical reefs. SPECS: Frame Width: 6-1/4″ Frame Height: 4-1/2″ Glass Diagonal Width: 5-3/4″ Skirt Depth: 3″ Skirt Width: 5-1/4″ Skirt Height: 4-1/4″