Made of carbon steel transfer balls, max load 35kg(77lbs) for different load requirements. Material structure: made of nylon Silent and wear-resistant material, sturdy and durable, strong, exquisite and fashionable appearance. Size (LxWxH): 48x32x20mm Positioning with screw holes on both sides, thickened material, strong bearing capacity and firm installation. Convenient and practical: smart and more trouble-free the ball can rotate 360 degrees flexibly, use smoothly, transport goods faster and save more time. Wide range of uses: Suitable for cabinets, shelves, displays, the transfer of furniture or mobile industrial equipment, etc. such as furniture casters, electric casters, office supplies, etc. It is convenient and quick to use and burden. Product Description High quality materials and craftsmanship Made of high quality carbon steel , smooth and resistance free, suitable for adjusting industrial transfer belts. Ball Transfer Units Ball Caster Transfer Wheels Material: carbon steel Color: silver Diameter (approx.): 70mm or 2.75" Mounting hole diameter: 55.5mm or 2.18" The maximum load: 35 kg Package includes: 4 x ball transfer units Note : Be sure to add lubricant during the maintenance period. Balls should be laid out horizontally and should have at least three (preferably four) balls. Please allow 1-3mm error due to manual measurement. Thanks for your understanding. Transfer unit for conveyor system Typically the design involves a single large ball supported by smaller ball bearings. ideal for most industrial transfer applications. They are commonly used in an inverted ball-up position where objects are quickly moved through a set of units, known as a table ball transfer, a type of conveyor system. Ball wheel transfer with flange This allows manual transfer to and from machines and between different sections of a other conveying system.