Product Material: Galvanized iron Ball Material: Nylon Ball Diameter: 16 mm (0.5 inch), 25 mm (1 inch) 16 mm Dimensions: 48 x 32 x 20 mm (L x W x H) 25 mm Dimensions: 75 x 50 x 30 mm (L x W x H) Package Includes: 4 x Roller transfer 8 x Screw - Delivery content: 4 x nylon furniture casters, 8 x screw, 16 mm or 25 mm diameter round ball transfer. Compact design allows installation in tight spaces. Includes two mounting holes for secure screw mounting. - High-quality materials: The ball transfer unit body is constructed from galvanized carbon steel, offering scratch resistance, corrosion resistance, and rust resistance for long-lasting durability. - Comfortable and practical: Features a 360-degree rotating ball for smooth, flexible movement. Enables effortless handling of goods, improving efficiency and saving time. Each caster supports up to 15 kg, suitable for a wide range of applications. - Quiet operation: Roller ball bearings are polished during manufacturing to ensure a smooth surface, allowing quiet and smooth rolling with minimal noise during use. - Wide application: Ideal for moving goods in both residential and industrial settings. Commonly used with sofas, display cases, carts, shelves, cabinets, kitchen appliances, scooters, conveyor systems, power systems, processing equipment, packaging machines, and auxiliary machinery.