4PCS 608-ZZ Ball Bearing Sealed Roller Skate SkateBoard Long Board Replacement NEW Feature: in order to ensure reliable and durable service life, the bearing is made of AISI 52100 chromium plated steel, which is more durable and better than carbon steel Long term durability, strength, but also double shielding to optimize lubrication and reduce pollutants. Widely used in medium load applications: size for skateboards, online skateboards, skates, skates, skates, skates, most types of general industrial equipment, printing paper reel, guide roller Fidget rotary fan motor, Rotary, shopping cart, wheel, luggage, wheelchair, office equipment, Advanced technology: dimensional tolerance check for assembly. Aperture: 0.315 in; Outer diameter: 0.866 in; Width: 0.276 in. Appearance design: bimetal. Accuracy class: abec-3 p6. Lithium grease range: - 22.0 f to + 230.0 F. Vibration noise level: Z1. may make you feel that when you hold it in your hand, it won't rotate quickly, but it will be released in actual use for a long time. Most bearings need to be "disconnected" to rotate properly. Package included: 4 x Ball Bearing