Durable and Flexible Ball BearingWith double ball bearing swivel heads, heavy duty swivel casters can rotate up to 360 degrees and move freely. The axle of the swivel casters have double ball bearings, which is better than traditional solid bearings. Furniture casters can therefore be used for several years, even for frequent and commercial use. Sturdy and DurableWith the elasticity of rubber casters combined with the metal structure which is sturdy and durable , furniture casters work securely. The polyurethane (PU) swivel casters neither scratch the floor nor leave marks on the floor and are safe for floors of all types. Flexible and NoiselessThe heavy duty trolley swivel casters can rotate 360 degrees. Industrial casters, like a skateboard, move freely and smoothly, even on a hard surface. The casters are sturdy and hardly make any noise. Easy to UseThe swivel casters come with the necessary screws and a screwdriver. You can put them together very quickly. Even if you are not natural DIY enthusiasts, it is easy to install them. Wide ApplicationThese heavy duty casters can be used flexibly for all applications. The swivel casters are suitable for DIYing your home, garage, and bedroom. Swivel casters are ideal for furniture, office chair casters, bed casters, coffee table casters, plant stands, shelves, toy boxes, coffee table casters, workbench casters; even for garden gate casters. Features: Heavy steel plate Double ball bearing swivel head Wheel type: black polyurethane, double ball bearings Rated load: 80 kg (20 kg per caster) Ideal for a wide variety of uses, from DIY to industrial applications (home, schools, shops and hospitals) Measurement: Diameter of industrial swivel casters: 40 mm; Caster width: 7 mm; Load capacity per caster: 50 kg; Total height (H): 50 mm / 2 inches; Card size: 45x40 mm; Board hole spacing: 35x30mm (long hole); Color: silver Size: as shown Quantity sold: 4 pieces About chromatic aberration: The goods sold are all taken in kind, but due to different lighting, monitors, etc. ., there will be a little color difference, which is a normal phenomenon, not a quality problem! About size: The dimensions of the products sold are all measured manually. Due to different measurement methods and tools, there may be an error of 1-2mm, which is normal! getveryrich