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 aluminum, 2-Step pulley, long time and durable use.4.40MM outer diameter,8mm aperture,10MM groove width,28.5MM Height.5.Suitable for v shape triangle belt, round belt.6.Application:Used in all kinds of machine transmission, double groove design speed can be adjusted according to different demands.Specifications:Material:AluminumColor:SilverOD:30MM/1.18 InchBigger OD:40MM/1.57 InchBore:8MM/0.31 InchGroove Width:10MM/0.39 InchHeight:28.5MM/1.12 InchJackscrew Thread:M5Brand Name: BQLZRSize:40x30x8MM/1.57x1.18x0.31 Inch(OD x Bigger OD x Bore Dia)Weight:52gPackage include:1x 2-Step Groove Pulley1x Wrench