certified 1/4" NPT 250 PSI Industrial air compressor / tank pressure safety relief valve. Also known as a "Pop Off" or "Blow Off" valve. This relief valve is manufactured in the United States and is stamped with "UV" & "NB" symbols. The relief pressure of this valve is set at 250 PSI and is accurate within + or - 3% of the set pressure. Specifications: This valve will relieve 214 SCFM Valve Inlet Threads: 1/4" Male NPT (measures about 1/2" in diameter) Total Valve Length: 1-3/4" Installation Wrench Size: 11/16" Features a silicone rubber soft seat relief valve to prevent leaks Max temperature: 250° F Solid Brass Construction Top quality made in the U.S.A Manufactured by Conrader