Quantity and specifications: 4 casters are included, you can choose the size according to your needs: 2 inches (40mm * 50mm * 78mm). High-quality material: Made of high-quality zinc alloy and PA material, it is lightweight and durable, moves quietly and smoothly, and is smooth and does not hurt the floor. EASY TO USE: The chair replacement wheels are easy to remove and can be installed in a minute. The braked wheels won't make too much noise in your living comfort and won't scratch hardwood floors. 360 degree rotation: special design, 360 degree rotation, with brake function, start and stop at any time, no noise when rolling, no interference in work. Wide range of uses: suitable for shelves, storage racks, trolleys, miscellaneous furniture, etc., and also suitable for hard floors, parquet and other floors. Dual wheel design - 360 degree rotation Note for installation: Remove the old swing. Aim for the interface and push the rollers out of the hard ground. VERSATILE USE: This caster is designed to be used as a replacement wheel for carts, furniture, workbenches, trolleys, etc. It is suitable for all types of floors in homes, shops, schools or hospitals.