The O'Neill Slasher Comp Vest is made of exclusive Nytrolite Foam that's more buoyant, 3 times lighter, drier, and offers better impact protection than conventional foam. The vest features a segmented foam core, anatomical flex points, integrated lumbar support, and strategic armholes for comfort and easy mobility. The reversible vest also includes mesh drainage and drain holes to keep you feeling drier. Not USCG approved. Men's sizes: XS(33"-35"), S(35"-37"), M(37"-39"), L(39"-41"), XL(41"-43"), 2XL(43"-45").O'Neill NytroLite Foam TechnologyAn exclusive process expands low-density polyethylene using nitrogen. This creates a foam that is 3 times lighter than regular PVC foam. It also absorbs 15-20\\\\% less water due to the closed cell foam structure. The resulting foam is about 10\\\\% more buoyant than PVC, meaning there is less foam in the vest but with the same buoyancy. | O'Neill Men's Slasher Competition Watersports Vest - Black - XL | The House