19 Splines Inside The Clutch Drum/Bell??ID of Spline Area: 14.4mm OD of Drum: 136mm ID of Drum: 125mm Pulley Diameter: 140mm Package Includes:1 * The Complete Driven Pulley Clutch Product Description Fits GY6 125cc and 150cc 4-Stroke Engine 19 Splines Inside The Clutch Drum/Bell??ID of Spline Area: 14.4mm OD of Drum: 136mm ID of Drum: 125mm Pulley Diameter: 140mm Package Includes: 1 * The Complete Driven Pulley Clutch We are your one-stop-shopping choice from replacement parts to Plastic Body Fender Kit accessories. Always ready to meet the end of Motorcycle & Powersports Lovers.