Feature thicker edges, corners and ribs to increase strength. Thinner flat surfaces allow for reduced weight. Roll-X cases have a depth of 17 3/4" and accommodate 19" rack mountable equipment with 3, 4, 5 and 6 rack space models. Made of polyethylene rotationally molded plastic with 2.5" wheels and industrial pull handle. Roll-X racks interlock and stack with each other. Sizes range from 2U space to 12U space.