CPAP masks are available in select styles that are nasal, full face and nasal pillow style. Choosing the right CPAP mask is one of the most important factors in achieving positive results from therapy and overall comfort. Nasal style masks cover the nose only and are the most commonly prescribed style. Full face style masks cover both the nose and mouth and works best for people that breathe through their mouth. This style is also recommended for people that are on high CPAP pressures or use Bi-Level (BiPAP). The nasal pillow style simply uses cushion inserts that seal around the nose and is the least invasive style of mask.