For the ultimate in comfort and variability, the BiPAP Auto line of sleep therapy systems automatically adjust to the user's pressure requirements on both inhalation and exhalation. With this type of BiLevel system, the physician prescribes a low and high pressure range for Inhalation (IPAP) and Exhalation (EPAP) making this the most comfortable of all sleep therapy options. These BiPAP machines also offer an optional humidification system for added patient comfort.