In mechanical engineering, an air booster is a device that is used to increase the pressure of compressed air. It works by taking in compressed air at a certain pressure and then using a piston or other mechanism to compress the air further, resulting in a higher output pressure. Air boosters are commonly used in a variety of industrial applications, such as pneumatic tools, air-powered actuators, and air-powered machinery. They can also be used to boost the performance of air compressors, allowing them to produce higher-pressure air without the need for a larger compressor.