Traditionally, the gear ratio in scooter CVTs is changed by the in-and-out rolling movement of the roller weights With the innovative DrDescription Traditionally, the gear ratio in scooter CVTs is changed by the in-and-out rolling movement of the roller weights. With the innovative Dr. Pulley sliding roller weights, the roller weights “slide” inward and outward in the Movable Drive Pulley (MDF) to change/extend the gear ratio.Dr. Pulley sliding roller weights provide the following advantages over traditional “rolling” roller weights:Eliminate abnormal wear in the high gear position. Enjoy a broader range of gear ratios.Experience outstanding acceleration and re-acceleration properties.Retain explosive low end acceleration and reach higher top speeds.Last longer than traditional roller weights while experiencing excellent CVT variator performance.U.S. patent no. 7276004. ? WARNING California Residents: Proposition 65 Warning Specifications Size: 15x12Available Weights: 3.5g