Non-marring knee pads, comfortable design with gel and gelfit foam, ergonomic shape that wraps the knee and upper shin. snapshell covers can be easily detached and are interchangeable, making this the perfect knee pad for all jobs. 2 in 1: use the knee pads with or without snapshell covers. maximizes pressure distribution to maintain all-day comfort. the height of the side panels greatly reduces knee twisting. eva rubber elastic straps that stay in place and provide comfort without cutting off circulation. 1680 denier abrasion-resistant fabric