608zz Bearings: Single-row bearing for supporting radial and axial loads. Shields on both sides keeping lubricant in and contaminants out. Zurability and resistance to deformity under heavy loads. 34,000 RPM limit with grease lubrication. It's suitable for use in skateboards, inline skates, scooters, and other skating applications. Bearings are Oil lubricated to be smooth. Item: 608-ZZ Ball Bearing Type: Deep groove ball bearing Lubrication: Oil Closures: 2 Shield, can/'t be removed and re-installed again Color:silver Material:carbon steel Size:8mm x 22mm x 7mm Package Contents: 25 * pcs 608zz ball bearings Only the above package content, other products are not included. Note: Light 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.