1Wide Application: The carburetor main jet is a wonderful replacement for GY6 50cc 139QMB Scooter and replacement for Keihin Carb PZ19 to meet your needs. 210PCS Total: The carburetor nozzle set includes 40, 42, 44, 45, 46, 48, 50, 52, 55 and 58 10 in total different kinds of size, sufficient quantity for you to replace. 3 Materials: The carburetor main nozzle is exquisitely made of advanced metal material without any burrs or other noticeable defects. 4Perfect Match: The carb nozzle set is designed according to the original standard for perfect fitness, direct replacement for the old or broken one. 5Easy to Install: The heavy duty carb main jet is specially designed with simple structure for convenient installation without any complicated tools.