Product Name: Ball Roller Bearings Type: 6001- Color: Silver & Black Material: Metal, Rubber Size: 28 x 12 x 8mm; Brand new and high quality, product is your best choice. It's time to replace your old, worn and damaged product. Outer Diameter: 28mm / 2.8cm Inner Diameter: 12mm / 1.2cm Thickness: 8mm / 0.8cm Weight: 210g/combination Package Contents: 30 x Split Ball Bearings Only 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 +/- 1-3 cm.