The S9 Elite™ is a whisper quiet, elegant and comfortable therapy system for the treatment of Obstructive Sleep Apnoea (OSA). The S9 Elite provides Continuous Positive Airway Pressure (CPAP) with Easy-Breathe™ Expiratory Pressure Relief (EPR) to prevent the collapse of your upper airway during sleep.

The S9 Elite uses the latest, easy to use technology to enhance the breathing comfort and reduce system noise. Designed for a more natural breathing experience, the S9 Elite’s enhanced Easy-Breathe technology delivers unrivalled, whisper quiet therapy from the device and the mask.

For more detail: http://www.resmed.com/in/products/s9_elite/s9-elite.html?nc=patients