1.The device adopts the whole and clearly-designed cross section of a Toyota A341E's automatic transmission to illustrate its internal structure and the gear-shifting power transmission process. 2.The internal mechanical structure and mutual assembly relation in the speed changer can be displayed externally through crafty disassemble and painting of different colors. 3.The transmission can be put to different places in the axial direction through manual swing pole. As a result, every part of the transmission can be observed. 4.It can help students study transmission structures and working principles, assembling and disassembling and examining transmissions, judging and troubleshooting mechanical failures. 5.The swivel stand is made in high-intensity steel and the surface is paint-coated. Self-retention wheels are installed to ensure that it is flexible and convenient.