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 inside the variator and therefore the heavier the rollers, 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 16x13mm – 4.4g You should research in what weight is best for your needs as simply going for the lightest or heaviest weight is not always the best option. We stock many different roller weight sets which offer different results in performance.