Prima Roller Weight Tuning Kit (15x12) This is probably the best way to go about tuning your CVT transmission! Included in this tuning kit are 12 sets of 3 rollers, for a total of 36 roller weights. These sets range from 2g to 13g. Combining 2 sets of rollers allows you to tune with a large variance of weights sets! For example:3x 10g & 3x 11g rollers (alternating weights in variator) gives you 10.5g roller set. DANGER: weights must be put in a 120 deg pattern! If not, SEVERE ENGINE DAMAGE WILL RESULT!!! TIPS: Lighter roller weights will increase RPM for any given road speed.Heavier weights will lower RPM for any given road speed. All of this, of course, must be tailored to each person's engine set-up & personal driving style!! Please refer to our handy and chart and for more info. and Brand: Prima compatible with: compatible with Yamaha Zuma 50 2-stroke, Jog 50 Various 40QMB 50cc 2-stroke scooters