Clutch Variator Front Set Fits For GY6 50cc Scooters ATVSpecificationsThis replacement clutch will fit most 4 stroke 50cc Chinese scooter brands.Almost all 4 stroke Chinese twist and go scooter engines use the common GY6 engine with engine code 139QMA or similar.This unit includes the drum housing, clutch shoes and rear pulley, it is a complete unit.Shoe Width 18mmDiameter of Central Hole 11.67mmOverall Height 70mmOuter Diameter of Drum 114mmInner Diameter of Drum 107mmDiameter of Shoe (approx) 104mmInner Diameter of Bearing 17.5mmOuter Diameter of the 2 Dished Plates 119mmStraight Shaft or Tapered Shaft? Tapered ShafNumber of Splines 22