The Kazbek Z87+ safety glasses were designed for long days and demanding conditions. These safety glasses have an unmistakable lifestyle shape, available polarized lenses and an anti-scratch coating. The Kazbek’s frame is constructed of a nylon composite material that can be tied into a knot. And while we don’t recommend tying yours into a knot, the rugged flexibility of the frame means you get a comfortable, yet equally durable, pair of safety glasses with an ANSI Z87+ rating. Plus, with the addition of Edge-Flex™ temples that conform to the side of the head, the Kazbek serves up a tailored fit. A thermoplastic rubber (TPR) nosepiece offers comfortable, non-slip performance. And the lenses block 99.9% of UVA, UVB and UVC rays. What more could you ask for in a pair of Z87+ safety glasses?