SSP-G 16x13 Roller Weight Tuning Kit for 50cc 4-stroke QMB139 engines - Includes 3g to 14g weight options. When it comes to adjusting your variator, there is no need to have tons of roller weights on hand for tuning. This roller weight kit includes 12 sets of 3 rollers for a total of 36 roller weights to adjust and fine-tune your variator. Directions for Use: Combine 2 sets of rollers in an alternating pattern , for example: 3 x 5g & 3 x 6g rollers (alternating weights in variator) gives you a 5.5g roller set. Please Note: You must install these weights in an alternating pattern, otherwise a severe imbalance in the variator will occur . These rollers are designed for tuning purposes only and we recommend that they are not used for long term use. Once you have determined the appropriate weight for your set up you should buy a complete roller set for permanent use. Please see our Warranty & Returns Policy.