Fisher & Paykel Forma Full Face CPAP Mask Pack with Headgear Size:Small The device provides inspiratory positive 41980 1633 The device provides inspiratory positive airway pressure and also has a backup rate to make sure that you get enough breaths per minute Usage Information: The External Battery Charger will charge one battery at a time while Fisher & Paykel's Glider Straps and and Easy Release Cord distribute pressure equally across the face and automatically adjust the mask alignment during sleep Finally the Forma features a new maintenance free Air Diffuser that disperses airflow away from the sleeper and sleep partners and minimizes exhaust noise