247Garden CO2/Argon Regulator w/Forged Brass Body, Nylon Washer, 4000 PSI Pressure Gauge, 0.5-15 SCFH Compatible for Indoor Gardening & Hydroponics Carbon Dioxide Gas, Draft Beer Brewing Forged brass body and bonnet for maximum strength Safety relief valve is set for safe operation No soldered joints for easy maintenance Sintered metal inlet filter to trap impurities w/ nylon washer