608 Full Ceramic Skate Bearing zirconium oxide One Bearing Full Ceramic Skate bearings that works in all skate applications like skateboard, inline skate, rollerblades, roller hockey, and even the 8mm quad rollers. These bearings can be used inline skate, rollerblade and roller hockey. These bearings are to be used for races and competitions, you will need 8 bearings for skateboards and 16 for all other skate applications.