Argon CO2 Regulator Bubble Flow Meter - Mig /Tig Weld Calibrated for Argon， Helium and Carbon Dioxide gases 2 inch pressure gauge for easy reading Flowmeter is back pressure compensated to ensure accurate readings when line restrictions are present. Polycarbonate flow tube and outer cover are impact resistant for maximum durability External safety pressure relief design No instructions providedPackage Included:1pcs Argon CO2 Bubble Flow Meter Regulator