The Harris® Model 55-2 flowmeter is designed to provide precise flow control in SCFH. For use with Argon (Ar) and Carbon Dioxide (CO2). It is compensated at 50 PSIG and calibrated for most common industrial gases. Provides accurate measurement of gas flow for gas-shielded arc welding and laboratory applications. This model features a sensitive needle valve for fingertip control and durable, easy-to-read, flow tube and cover. It is equipped with a tamper-proof, self-reseating pressure relief safety valve. It has a 1/4" NPT (M) inlet connection.