1pcs* 40Teeth 3M Aluminum PulleysType:40-3M-10 BFPitch:3mmTeeth Number : forty teethBore:D Type 8*7.5mmOutside Diameter (OD): 37.45mmFlange:doubleMaterial:Aluminium AlloyFit for Belt Width :10mmPackage List ing Includes as Follow:You can want differernt Bore diameter and Width and Quantity According to the manufactured from your choice, I will manage your order.and Send to you! (The 40Teeth 3M Pulleys have bore diameter 8*7.5mm)(please prefer bore diameter and Belt width and Quantity)