Malossi HT Rollers are made with CPT with a specific formula and are capable of varying your scooter’s transmission ratio and perfectly regulating its speed and acceleration. The weight of the rollers become the centrifugal force and therefore the higher the rollers weight, the lower the gear change time and vice-versa therefore by lowering the roller weights the engines RPM increases and by increasing the roller weights the RPM decreases. Specification: Set of 6 x 19×15.5 – 11g