Made of two stage aluminum alloy shell, designed with light weight and high strength,adopting single box and single axle structure, simple structure,Full helical gear and full grinding gear design, low noise and high reliability; Using self-made high performance fast shift synchronizer, flexible and portable operation; The side force taking window can be matched with the force taking device; has become the standard speed variator of Yutong high end business car and Futian high Rui light card