Alvin® Step-Design Roll File. Unique step-design base includes twenty-four 3 1/8" x 3 1/8" openings for easy access to rolled maps, plans, drawings, and tubes. The four swivel casters give it high mobility. Constructed of white plastic-coated heavy-gauge steel rods. Includes custom-fitted bottom dust protector. Overall dimensions: 32"h x 21"w x 14"d. Assembly required.