Tripp Lite's SmartRack SRCASTERHDKIT is a heavy-duty rolling caster kit used to maneuver rack enclosures and 4-post open frame racks to their desired location. The heavy-duty casters (750 lbs. per caster rating) allows for a weight limit of 3000 lbs. both stationary and rolling. The kit includes 4 casters and mounting hardware. Note: Casters are intended for minor position adjustments and are not designed for moving racks over long distances.