The CPAP mask (also called an "interface") is perhaps the most important part of CPAP therapy. Comfort and quality of air seal are vital to maintaining consistent use and quality of treatment. Three styles of mask are available through several manufacturers. The most popular and widely available masks are made by Philips-Respironics, ResMed, and Fisher-Paykel. Nasal pillow masks are the smallest interfaces, and fit snugly just inside of the nasal passages. Nasal masks fit over the nose like a small cup. Full face masks cover both the nose and mouth, and are generally used when mouth breathing is present or when mouth air leaks develop with nasal pillows or nasal masks. Patients should be fitted for their mask by a sleep technician so that optimum fit and comfort are established. A Kramer sleep technician or sales representative is available to assist you in this if desired.