Easy to Use, Minimal Parts, Superior Comfort The importance of sleep cannot be overemphasized. It is essential that our sleep provides our body with a much needed recuperative phase. During sleep, our bodies use this time to repair, and rejuvenate. One can argue that sleep is as important to overall health, as diet and exercise. It is because of this the Eson is the ideal mask for sleep therapy. Simple, yet thoughtful design, as well as minimal parts, allows you to use the mask with ease. Here are a few features that show why the Eson is so popular. ROLL FIT SEAL Eson's single-piece Nasal Seal Cushion rolls softly to auto-adjust during sleep to reduce pressure points on hard to fit areas, maintaining a perfect seal and consistent comfort. The RollFit Seal is the reason this mask provides stability, and consistent seal, even at higher pressures. ERGOFIT HEADGEAR Eson's breathoprene ErgoFit Headgear is designed to provide soft stability by placing the focus of its anchor-point at the rear of the head, this the headgear to remain stable, even with active sleepers. Smartly positioned velcro tabs & 'Easy Clip' Hooks provide a fast placement and removal without the need of readjustment. Eson has two headgear sizes available: All Small Eson Full Face masks come with Small ErgoFit Headgear. All Medium and Large Eson masks come with with Medium/Large ErgoFit Headgear. EASY FRAME The Eson low profile stable frame system is both durable and minimal in size. Because of this, the Eson allows for a clear line of sight. This feature opens up activities such as watching TV, reading a book, or tablet while wearing the mask. The Eson mask frame fits all three seal sizes and has an Easy-Clip frame attachment, which makes disassembling the mask for cleaning, a breeze. Quiet Intentional Leak Ports The Eson Easy Frame comes with a Q Cover elbow vent for remarkably quiet operations, and flow diversion, that keeps the airflow away from you, and your partner. The 360 rotating ball-and-socket elbow allows for a free movement during and helps manage tubing placement. In summary, we think the Q Cover and diffuser make this one of the quietest masks on the market.