Features: 1.Every product has a unique Manufacturing Part Number label on the inner package that proves it has been qualified,which include Part Number,Model Number and inspection date information;2.If you have any questions about the item,please provide us the Manufacturing Part Number for checking,your profits will be guaranteed.3.Made of Bearing Steel, with groove.4.OD:6mm, ID:30mm, Load-bearing: 355KG.5.Groove bearing pulley, use for high-grade automatic sun room, mobile garage doors, transmission machinery, etc.6.High sealing performance, high operation performance.Specifications:Material: Bearing SteelColor: Black + Silver name: BQLZRGroove :U GrooveLoad-bearing(each): 355kgInner Diameter(ID): 6mmOuter Diameter(OD): 30mmOverall Size: 6 x 30 x 8mm/0.24 x 1.18 x 0.31 inch(ID x OD x H)Weight: 25gPackage include:1 x Bearing Pulley