The structure characteristics of single shaft, full synchronizer structure. 1/2 file, 3/4 file by double cone synchronizer, gear synchronous large capacity, flexible and convenient. Constant meshing helical gear drive, large carrying capacity, low noise, long life. High speed gear with fine pitch design (end overlap coefficient epsilon >2), stable meshing, low noise. Small center distance (148mm), small volume, light weight. Can be equipped with a side force to meet the needs of vehicle modification. Single rod control and double lever operation can be realized. Applicable models of this series of transmission is suitable for trucks, buses, special vehicles and other models.