This low-stretch static rope is a favorite of cavers and search-and-rescue teams. Kernmantle construction--braided nylon sheath over nylon strand core--offers low static elongation and superior abrasion resistance. Max-Wear nylon sheath offers extra-durable wear stiffer than most ropes, making it less knotable. Diameter is 11mm 0.43 in. which is 7/16in.