Archrock, Inc., formerly Exterran Holdings, Inc., is engaged in providing natural gas contract compression services to customers in the oil and natural gas industry throughout the United States. The Company also provides aftermarket services to customers that own compression equipment in the United States. It focuses on Natural Gas Contract Compression Service, and Aftermarket Parts and Service. Its Compression Services offers inventory of compressor packages ready for deployment, and comprehensive fleet with the technology from an aggressive and continuous new build program, among others. Its services include Compression Services, Aftermarket Services and Used Equipment. Its Aftermarket Services maintains ready inventories of critical engine, compression and gas compressor package parts located throughout the United States. Its used equipment include AJAX, Arrow/Ariel, Caterpillar/Ariel, Caterpillar/GE Gemini, Rotary Screw and Waukesha.