Keih Main Jets used in many types of carbs used on many motorcycles and scooters.
These wil fit the PD GY6 Carbs 24mm used on GY6 150 Scooters, also main jet for CN250 engines used on scooters, atvs and UTVs, also main jet for Linhai engines
The CG Vertical engine carbs also use this as main jet. The CG engine is found on many motorcycles and atvs from CCW, SYM, Honda just check your main jet to make sure you have this style.