This is a used Mirage Quattro Full Face Mask - it is a size small. This is a highly popular mask although I didn't like it as I have a very small face and the mask kept hitting the inside corner of my eye. Otherwise it was great. It has an innovative design that features an advanced seal that adjusts for a better fit. The new MicroFit dial allows the mask forehead support to be adapted to the user. About 40 percent of people who use a CPAP machine and just about all BiPAP machine users lose pressure directly from the mouth. This happens usually through leaks from the mouth or via mouth breathing while wearing a nasal mask. The resulting loss in pressure may bring about flu-like characteristics, inadequate sleep therapy, and disrupted sleep. Since the Mirage Quattro full face mask covers both the nose and mouth it prevents pressure loss from mouth breathing thereby improving both your comfort and your sleep therapy. The Mirage Quattro full face mask is a great solution if you have frequent nasal congestion or it can be useful to have on hand in case you catch a cold or have bothersome allergies. Features & Benefits

• Dual Cushion designed for an advanced seal that will conform to your face with movement.
• New refined air vent lowers noise by over 50%.
• Set and forget headgear.
• New MicroFit dial that allows the mask forehead support to be adapted to the user.
• Available in 4 sizes including new extra small size.
• Membrane at the chin to support jaw movement.
• Reduced mask parts for quick and easy cleaning.

MicroFit Dial The MicroFit dial allows CPAP users to find the right fit using 24 small incremental adjustments. The dual-wall cushion and forehead move in tandem as the dial is turned. This design is intended to address difficultly with "first time" fittings and ensure that is it not necessary to over tighten the mask's headgear.
If you are looking for parts this has
1. The forehead pad which sells online for $7.00 plus shipping
2. The headgear clips which sell for $6.90 plus shipping
3. The Cushion Clip which sells for $14.00 plus shipping
4. The cushion which sells for $45.00 plus shipping
5. The Forhead Support which sells for $17.50 plus shipping.
I could go on but check out this page and you'll see all available parts http://www.cpap.com/productpage-replaceparts/resmed-mirage-quattro-full-face-mask-headgear.html