Appropriate for:for 50cc 4-stroke QMB139 Street Scooters with 12 inch rear wheelOE Number: Does Not Apply Belt Girth: 740mm / 29.13" Belt Width: 17mm / 0.67" Belt Thickness: 8.8mm / 0.35" Specification:Drive Belt is used to transmit power and improve work performance, ours drive belt have better smooth transmission and better quietness.Function:A good replacement for the old or broken one, match for the former powersports drive belt.Material:Rubber, FiberInstallation Instructions:Direct replace for the old or broken powersports drive belt, match for the former part.Item List:1 Pcs Drive BeltPlease Notice: If the drive belt is slightly big or small, we recommend you adapt the length of the belt by adjusting the clutch tightness. Please allow 1-3mm differences due to manual measurement. This is Non-OEM product, accessory Only!