Electric air compressors are units that plug into an electrical outlet or units that run on a battery. Portable air compressors inflate tires and supply power to air tools. Stationary air compressors install in a fixed location and are often connected to a distributed air system. Rotary screw air compressors provide continuous air supply in facilities with constant air-flow needs. Vehicle-mounted air compressors give service vehicles ready access to air power out in the field. Laboratory and health science air compressors deliver clean air in sensitive environments such as dental offices.