The mechanical puzzle Variator of the UGEARS STEM lab collection is a fully functional wooden replica of a Belt-driven Friction Cone CVT. The Cone CVT varies the drive ratio by moving a wheel or belt up and down the axis of conical roller. In the UGEARS model kit Variator, the belt, powered manually via the reducer, transfers the rotation to the driven cone pulleys. Use the transmission fork to change gears and observe how the speed of the driven cone pulley drops or rises while the drive cone pulley’s speed remains the same. Due to the open design of the model, you will be able to see the whole process. With DIY wooden puzzle Variator from the STEM lab collection you can learn and comprehend one of the most important parts of a car without soiling your hands in machine oil!