Fitment: Fits GY6 49cc 50cc 4-stroke 139QMB Engines with Long or Short Case. Such as Baja, JMstar, Jonway, Lance, NST, Peace, Roketa, Sunl, Tank, TNG, Vento, VIP, Taotao and many others.
Rear Clutch Specification:22 splines inside the clutch bell; Assembly Comes with 2000RPM Clutch Springs. OD of bell: 117mm, OD of pulley: 119mm . Pulley Needle Bearing: HK172518RS . ID of bearing in clutch shoe assy: 12mm (6901RS)