Frequently, a Helical Gear Box has numerous rigging proportions (or basically "gears") with the capacity to switch between them as speed fluctuates. This exchanging might be done physically (by the administrator) or consequently. Directional (forward and turn around) control may likewise be given. Single-proportion transmissions likewise exist, which essentially change the speed and torque (and in some cases bearing) of engine yield. In engine vehicles, the Helical Gear Box normally is associated with the motor crankshaft through a flywheel or grip or liquid coupling, incompletely in light of the fact that interior burning motors can't keep running beneath a specific speed.