A gear is known as a rotating machine. Gears have cut teeth, known as cogs, which fit together with another toothed part to transmit torque. Geared devices can change the speed, torque, and direction of a power source. The teeth of gears are shaped to lessen wear, vibration and noise, and maximize the efficiency of power transmission. Gears are indispensable to daily living and can be found in mechanical devices as well as everyday household objects. Gears are used in clocks, cars, odometers, scales, conveyor systems, meters and VCRs among others. Manufacturing companies rely on several various sizes of gears for production.