CO2 Flowmeter Regulator, 1/2 – 12 LPM CGA-320 Handtight Nut and Nipple. Chrome-plated brass body with all brass high-pressure chamber. Maximum rated inlet pressure 3000psi. Durable neoprene diaphragm. Internal reseating relief valve protects against over-presurization. Sintered filter for additional safety and to extend regulator life. 2″ diameter gauge. UL listed. Polycarbonate inner and outer tubes provide greater accuracy and durability. Includes plastic swivel hose barb. Packaging: 1/Each.