Speed reducers, also gear reducers, are mechanical devices that mainly serve two purposes: to increase the amount of torque produced by an input power source for a greater amount of usable work and reduce the speed of the input power source for the desired output speeds. Reduction gear comprises of a set of rotating gears that are connected to a wheel work. Speed reducer accessories and parts are used to repair damage, improve the device’s functionality and enhance compatibility in motorized systems. Speed reducer replacement parts include backstops, torque arms, flange coupling kits, bushing kits, shaft kits and double shaft kits. Torque arms are installed to connect speed reducers and drive mechanisms while backstops prevent directional reversal. Reducer parts and accessories are subdivided to make it easy to assemble and mount the gear unit.