Naraku Super Transmission Kit Eco for 50cc QMB139 engines. Kit includes: Variator, Clutch and Clutch Bell. Please see our Warranty & Returns Policy. Roller Weight Size: 16x13mm (6g) Variator Outer Diameter: 88mm Clutch Drum Number of Splines: 22 Clutch Drum Spline Inner Diameter (peak to peak): 11.10mm