Upgrade kit to change the original one-petal reed set-up to a more efficient two-petal one. Highly recommended in conjunction with a big bore carb. The considerably larger intake area allows a larger volume of mixture to enter the crankcase. This results in a better gas flow into the cylinder which in turn results in a higher power output throughout the rev range. Kit consists of a reed cage, two petals, inlet manifold and small parts. Suits all Dellorto and Amal carbs from 12 to 21mm choke size. Compatible with: - Aprilia: SR 50 Min.AC 94-_S - Mbk: Booster 50 euro 0-1_S, Booster 50 euro 2_S, Stunt 50 euro 0-1_S, Stunt 50 euro 2_S - Yamaha: BW's 50 euro 0-1_S, BW's 50 euro 2_S