Clean Air Power Limited, together with its subsidiaries, designs, develops, and markets and second-generation MicroPilot engine systems to heavy-duty and compression-ignited engines in the United States, Europe, Russia, Australia, and internationally. The company operates through Dual-Fuel and Components segments. It provides Dual-Fuel energy management systems that enable heavy duty diesel engines to operate on a combination of natural gas and diesel. The company also offers natural gas valves, filters, and other specialist components for natural gas engines; hydraulic transmission valves; and gas engine components that include coalescing filter assembles, shut-off valves, gas injectors, pressure regulators, turbo air bypass valve assemblies, gas injector blocks, and porting tools. In addition, it provides three technologies for controlling the pollutants from stationary gas and diesel powered engines, which include oxidation catalytic converters of hydrocarbon and carbon monoxide (CO) emissions; 3-way catalytic converters to reduce nitrogen oxide (NOx), CO, and NMHC emissions; and selective catalytic reduction of NOx emissions. Further, the company designs and manufactures after-treatment systems for products that are used to control emissions from spark-ignited gas engines running on natural gas from vehicles. Clean Air Power Limited was founded in 1991 and is based in Leyland, the United Kingdom.