Locking casters: Double locking mechanism with brakes for enhanced safety and stability. Features a dual lock system for swivel and wheel movement. Swivel casters: Dual swivel design allows smooth 360-degree rotation and easy maneuverability. Equipped with brakes for secure positioning. Premium material: Constructed with industrial-grade electrophoresis-coated brackets and durable polyurethane wheels. Resistant to corrosion and rust. PU wheels protect floors, move quietly, and leave no marks. Double locking and ball bearing design: Ensures stability and smooth movement. Provides excellent control when navigating tight spaces. Wide application and easy installation: Simple to install with built-in stopper for added safety. Ideal for use on carts, furniture, wire shelves, storage racks, workbenches, toolboxes, wheelbarrows, and more. Product Name: Universal Wheel Size: 12 x 9.6 x 3.5 cm Color: Black Material: Polyurethane Package Contents: 4 x Universal Wheels Note: Light reflection and different displays may cause the color of the item in the picture to appear slightly different from the actual item. Measurement allows an error of +/- 1-3 cm.