Sierra 740 Flo-Trak is an exhaust flow controller that can be used to directly measure and control the mass flow of various gases, including air, nitrogen, natural gas, CO2, Argon, Helium, and Propane. It features a self-heated platinum resistance temperature detector (RTD) immersed in the flow, which senses the flow and provides excellent rangeability and low flow sensitivity. The device is not liable for any damages or personal injury resulting from the use of oxygen gas and must be cleaned to the degree required for specific oxygen flow applications.