Excellent Materials and : Our caster wheels are made from industrial-grade electrophoresis brackets, precision , and durable polyurethane wheels, which gives them a long lifespan and makes them to protect against corrosion and rust. PU wheels does not hurt the ground, flexible movement, leaving no marks on the floor. Locking Casters: Dual locking and double ball bearing for maximum safety. Our stem casters have brakes to further safety and stability, a double lock mechanism for both swivel and wheel rotation is set in place. Swivel Casters: Castor wheels can rotate that ensures maneuvering and turning, the wheels can transport heavy items smoothly from one place to another. Casters 4 Heavy Duty: Solid steel support is extremely durable. Each 2 inch caster wheels can bear 150lbs of load, making a total of 600lbs load capacity for 4 wheels. Wide Use and Easy Assembly : Our 2 inch industrial casters can be used for both indoor and outdoor equipment. Casters and wheels can use for cart, furniture, wire shelving racks, storage shelves, workbench, toolboxes, trolley etc. It comes with spring washers, mounting nuts and miniature wrench for easy installation. Colour:Black Material:PVC + metal Package Contents: 4X 2inch Casters Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.