High Quality Casters Set Of 4:4 pcs swivel casters with double bearings and locks.Made of Polyurethane and Steel,PU rubber wheel keep quiet and wear-resistant, quite movement without scratch.More Flexible:The swivel casters rotate 360 degrees which makes turning the mating equipment possible, is perfect compatible with transporting light furniture and displays quietly and safely.Standard Metric Size:Stem size: M8 (8mm)-1.25 x 1inch,Threaded length:25mm/1inch, Wheel diameter:40mm/1.5inch.Heavy Duty Casters:Loading up 80 lbs each caster wheels and 320 lbs as a set of 4. Commonly used compatible with shopping carts, trolleys, office chair, cabinets, bookshelves, work tables, underbed storage, stands, movable furniture etc.Double Locking Brakes:The safety dual locking brakes lock both the swivel and wheels efficiently.Built-in precise ball bearings support free rotation and rolling smooth,bid farewell to harsh noise.Designed compatible with outdoor, hardwood floors and carpets.Colour: blackMaterial: PUPackage Contents:4 x wheels with locking brakes8 x nuts1 x wrenchOnly the above package content, other products are not included.Note: Light shooting 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.