UGears Dynamometer is a dynamic and unique model. It operates using the pneumatic principle by making use of air to wow the user. This UGears model operates by transforming air pressure into motion. When you blow onto the top gear a system of lever spins the wheel of the arrow. One interesting thing about this model is that it can be used as a game between your family and your visitors. You blow on top of the gear and the arrow spins and comes to rest on a particular task that the blower will be asked to perform. It is a good educational model.