Abec 7's have the most effective combination of the tightest tolerances and high quality materials equipped with a single shield. These are great allround skate bearing. Features: Removable steel c-ring allowing you to service your bearings Heat treated non-contact shield Balls are heat treated and honed to HRC 62-67 hardness for superior durability Raceways heat treated and honed for maximum speed 8mm inline bore Made by BSB