HYDROPONIC BEARINGSHigh Quality Steel Precision BearingsHYDROPONIC Precision Bearings are constructed in steel, each one housing seven lubricated balls which are designed to disperse the weight of a load and ease tension between the wheels and the axle. Characterized by an 8mm core, a 22mm outer diameter and a 7mm width, these bearings are the industry standard and match up with nearly every skate wheel out there.*ABEC 3 WHITE: For the new skater, who is getting used to the speed and movement of the skateboard.