This Jet Kit is for our 20mm Carb (and 18/20mm Keihin's) and includes the following sizes (stock size is an 89): 75, 78, & 80. This kit is good for small bore models - 72cc and below. IF YOU DO NOT HAVE ONE OF OUR 20MM CARBS OR A 18/20MM KEIHIN, DO NOT BUY THESE AS THERE ARE NO RETURNS/EXCHANGES ON JETS AND THEY ONLY WORK ON THE CARBS MENTIONED.