Features: 1. Each product has a unique Manufacturing Part Number label on the inner package indicating it has been qualified, including Part Number, Model Number, and inspection date information. 2. If you have any questions about the item, please provide the Manufacturing Part Number for verification. 3. Single load bearing capacity: 45 kg (99 lbs). 4. Nylon ball roller: Quiet, wear-resistant, non-conductive. 5. Steel shell: High quality, durable, and well-shaped. 6. Dimensions: 24 x 39 mm (0.94 x 1.54 inches) (Diameter x Height); Ball diameter: 15 mm (0.59 inches); Screw thread: M8. 7. Suitable for use in conveyor lines, home appliances, transmission systems, processing equipment, wooden cases, furniture with transfer capabilities, workbenches, and similar applications. Specifications: Material: Nylon & Steel Color: Silver Product Name: BQLZR Dimensions: 24 x 39 mm (0.94 x 1.54 inches) (Diameter x Height) Ball Diameter: 15 mm (0.59 inches) Screw Thread: M8 Weight: 188 g Package Includes: 4 x Ball Transfer Bearing Casters