This mechanical transmission model contains 6 common transmission modes: belt drive worm gear drive chain drive spur gear drive bevel gear drive friction drive Working Principle: The instrument is driven by DC motor. Firstly the DC motor drives the worm through the belt to complete the belt drive and then the worm drive worm gear realizes the worm gear transmission. After the above two decelerations the worm wheel shaft drives the next chain drive. Next driven by the spur gear drive bevel gear drive and friction drive Usage: When using this instrument you need to have a DC power supply. After the instrument is placed horizontally on the table insert the end of the connecting wire with the plug of the instrument into the power socket of the instrument and connect the other end to the DC output of the power supply. Adjusted on DC6V turn on the power the instrument will enter the working state adjust the power supply to change the operating speed of the instrument change the polarity of the instr Suitable for people over 14 years old Inspire Curiosity & Creativity – Not only a teaching aid but also an inspiring science gift. Encourages logical thinking, hands-on skills, and a deeper interest in physics, making learning both effective and enjoyable.