Package & Size: 16pcs 608-2RS ball bearings Size: 8x22x7mm, rubber sealed deep groove. Wide Application: These 608-RS Ball bearings are commly used in skateboard wheels, longboard wheels, spitfire wheels, scooters, inline skates, roller skates and other skating applications. Material: Carbon steel, durability and resistance to deformity under heavy loads. Attention : We Used some rust protection oil on the bearings,if you dont want the bearings get rusty pls do notput it on the damp place.also when use you'd better use gloves to touch the bearings to prevent it get rusty, asyour finger with sweat. With shields - This 608-Rs bearings with rubber sealed Shields on both sides keeping lubricant in andcontaminants out. Overall, the features and advantages of 608-2RS ball bearings make them an excellent choice for smallmachinery applications that require smooth, efficient operation and high durability Carbon Steel Material Double Rubber Sealed for lubrication Single-Row Bearings Package Included: 16 Pack Specification Inner Diameter: 7mm; Outer Diameter: 22mm; Height: 8mm Application Use: Skateboards, inline skates, scooters, roller blade skates, etc.