Supplied-air compressors and ambient-air pumps work with SAR (supplied-air respirator) components to provide safe breathable air to workers in environments with low oxygen levels or compromised air quality. Compressors fill cylinders and tanks. Pumps are placed in an area known to have breathable air and pull ambient air from the environment to move it through the filters. SARs attach to filters and pumps using an airline that moves breathable air to the respirator.