Easy to install: Screw swivel casters, universal casters with brake, set with nuts and wrenches, the upper wave plate is an octagonal wave disc, easy to install Heavy duty (load capacity): A single wheel can carry 150lbs, four wheels can carry more than 450lbs, easy to push, labor-saving. They are screw casters, threaded stem swivel casters, flexible rotation, safe and reliable. Smoothly moved with no marking, won't harm your wooden floor, no noise, the surface of the rubber wheel is soft and better protects the ground. These casters are widely used, generally used for workbench, cart, trolley, shelf, wooden cabinet, furniture, home appliances, etc