All Bones® Bearings are Skate Rated™ to our precision “tolerances” to give you the absolute maximum speed and life possible, not “ABEC” rated like bearings designed to operate in motors or normal machinery. The superb quality of Bones® chromium bearing steel races with their mirror like “super finish,” removable, non-contact rubber shields, high speed, precision molded ball retainers, and Bones Speed Cream® lubricant provide unequalled roll and ease of maintenance. So, carefully install them in your wheels and you’re ready to roll.