ROCKY XRB BOOT REALTREE EDGE 7MM 8 Made for the extreme outdoors, the Rocky XRB features a 3D TPU molded shaft and durable rubber foot, ensuring comfort, durability and warmth. The waterproof vulcanized rubber construction keeps you dry and holds up to difficult terrain, while the Dri-Blaze thermal insulation keeps you warm. A Vibram outsole provides underfoot stability while on wet or rocky terrain. These 16� boots have a removable PU footbed that is easy to clean. The Comfort Cushion and memory foam add stability and comfort on long days.