191HE-150 medium duty flowmeter regulators are designed for MIG & TIG applications to provide accurate regulation of gas flow. They are also ideal for commercial, industrial and laboratorial applications. Combination of regulator and flowmeter as one compact unit. Regulator is preset to 50PSIG. Piston-type construction. Body machined from class "A" brass. Internal pressure relief valve. Polycarbonate flow tube and hood are impact resistant for maximum durability and service life. Calibrated for argon, Co2, helium, nitrogen, air, and 75% argon/25% CO2 mix gases. Backpressure compensated o ensure accurate readings when line restrictions are present. Sintered bronze inlet filter. Conforms to CGA E-4 standard for gas pressure regulators.