Комплект зъбни колела
Gelsonlab HSTM-059 Education Science Toys Комплект зъбни колела experiment
This Комплект зъбни колела uses rack, belt, turbine, vortex rod, umbrella gear, flat gear and other transmission modes, through experiments to understand the advantages and disadvantages of various transmission devices, such as noise, transmission ratio and change of transmission direction.