XS Scuba Frameless diving masks are lighter, lower in volume, and more streamlined. As a class, they enjoy more popularity than ever before. Large single window for unobstructed view. Easy-to-adjust ratcheting buckles. Double, feather-edged sealing skirt. Made of hypo-allergenic silicone for comfort and longevity. Same design as many tech diving brands - Compare with Halcyon Masks - Same Silicone Quality, Nearly Identical in Design, Less Expensive for sure. Fits nicely in your Drysuit pocket for the required back up mask.