This RollerBones Bearings is a 608 8mm bearings with black nylon dust cover, skate rated and factory pre-spun with high precision races, hardened steel balls, delrin retainers and a light lubrication for a smooth and fast roll. Available in 8mm only, 16 pack. Rolls better than most Swiss Bearings! AN INCREDIBLE DEAL FOR YOU! This item may not be pre-packaed when delivered.