Double shielded bearings with good axial and radial support performance, a durable choice for high-speed rotation. 608ZZ bearings are made of chrome steel for durability and resistance to deformation under heavy loads, and are double shielded to keep lubricant in and contaminants out. Dimensions suitable for use in applications such as skateboards, inline skates, and scooters; Fits most skateboard wheels; Pre-lubricated, no maintenance needed. This single-row bearing is built to support radial loads and has a rotational speed limit (RPM) of 34,000 with grease lubrication. Applications: Used in a range of applications from agricultural machinery to transport equipment, robotics, dental equipment, elevators, rolling mills, ship rudder shafts, and crushers, among others. Model: 608ZZ ABEC-7 Bearing Material: Steel Size: 22 x 22 x 7 mm (Inner diameter 8 mm) Color: Silver Package includes: 15 x Skateboard Bearings 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.