The ATS TorquePro 2000 is an on-demand propane-injection system that's actuated by boost. It mounts under the hood and needs to have coolant hoses run though it to warm and vaporize the incoming propane. The propane is not inducted under pressure, but is drawn in by the engine airflow from a low-pressure vapor line. Two very important considerations are where the inlet orifice is placed and the length of the vapor line, which must be less than 3 feet long. An adjustable boost switch is used to activate the unit, which also has an on/off switch. There are several safety interlocks to prevent propane from entering the engine before the correct moment.