The Differential is an interactive puzzle kit to help learn and better understand the workings of a car differential.  The Differential was designed to ensure that the drive wheels sitting on the same axle rotate with a different rate and cover different distances at the same time. This mechanism allows the car to make turns without the wheels skidding, prevents wheel-slip, reduces tyre wear, and makes entering and going out of turns easier for the driver. Having assembled the Differential, you can unblock it pushing the lever in position 1 (Up) and set both wheels in motion by rotation of the drive gear or the wheel. The Control lever regulates the smooth locking of the left and right wheels independently by turning left or right respectively. In the “down” position of the lever, both wheels are linked in a rigid coupling and can either rotate together (propelled by the drive gear or a wheel) or lock simultaneously (by the lever of the wheel).