MAIN JETS FOR TUNING.
MANY SIZES AVAILABLE.
These Jets are used in the 125cc+ etc.. 2 and 4 stroke Scooters, ATV's, QUADS (152QMI,157QMJ etc) and Chinese GY6 125cc+ and Chinese GY motorcycles etc...
These can be used when you add a free-flow air filter, bigger cylinder, port your intake etc..