Traditionally, the gear ratio in scooter CVTs is changed by the in-and-out rolling movement of the roller weights With the innovative Dr Description 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. 24×18 roller weights fit a variety of street scooter models including the Honda Elite 250 (CH250). WARNING California Residents : Proposition 65 Warning Specifications Size: 24×18 Available Weights: 22g