American made brass valve with removable clip for easy maintenance of inner valve. Machined C360 brass body. 302 stainless steel spring. 15% glass-filled teflon poppet. 1 PSI cracking pressure, maximum pressure: 500 PSI, maximum temperature: 450°F Thread seal applied or supplied for valves with NPT threads. Please note: NPT sized valve threads will not correspond to standard sizes. Please see our attached charts or message us with questions. 1/2 NPT size (lower threads) measure close to 7/8" The "compression" or "tube" size is easy to determine by measuring the tube or line that connects to the top of the check valve. The outside diameter of the tube or line IS the "compression" or "tube" size. Compression / tube size thread diameters will not correlate to standard measurement. 6 month no hassle warranty Sellerocity American Made Brass Check Valve 1/2 NPT Size X 3/8 Compression Tube Size with Standard 1/8 NPT-F Unloader Port