Tripp Lite's SmartRack SRCASTER is a heavy duty rolling caster kit used to maneuver rack enclosures, wall-mounts and 4 post open frame racks to their desired location. The kit includes 4 casters (heavy duty 550 lb per caster rating), installation guide and mounting hardware. The kit comes standard with all floor standing rack enclosures (48/45/42/25/12U). Note: Casters are intended for minor position adjustments and are not designed for moving racks over long distances.