Dr. Pulley Performance Variator Assembly V282201 for the Kymco Xciting 500 and Kymco MXU 500. Specifically Designed Ramp Shape Extended Ramp Length Adjustable Boss Length Racing Type Ramp Plate Includes Instructions. Includes Slide Pieces. Does Not Included Roller Weights. Drive Face Outer Diameter (A): 150mm. Boss Inner Diameter (C): 22mm. Boss Outer Diameter (B): 28.9mm. Ramp Plate Inner Diameter Valley to Valley (D): 21.90mm. Ramp Plate Inner Diameter Peak to Peak (E): 19.9mm.