OD of Drum: 136mm??ID of Drum: 125mm 19 splines inside the clutch drum/bell Compatible with GY6 150cc 4 stroke engines ONLY,Kazuma 150cc full auto ATVs. Check Pictures and Measurements To Be SureThis is The Correct Clutch for Your Application. ATV clutch – 19 spline – GY6 150cc, Rear clutch for GY6 150 engine OD of Drum: 136mm??ID of Drum: 125mm 19 splines inside the clutch drum/bell Used in some ATVs Fits GY6 150cc 4 stroke engines ONLY Fits Kazuma 150cc full auto ATVs Package Includes: 1X Rear clutch Compatible with GY6 150cc 4 stroke engines ONLY,Kazuma 150cc full auto ATVs. Check Pictures and Measurements To Be SureThis is The Correct Clutch for Your Application. Read more Read more