SharkBite U2016-0000LFA Lead-Free Brass Push-to-Connect Check Valve, 3/4"SharkBite Check Valve is general purpose, spring loaded check valve that are easily installed on Copper, CPVC, PEX and PE RT lines. This can be installed horizontally or vertically and prevents the reverse flow of water through the water supply line. 3 4" x 3 4" For use with OD CTS copper, CPVC Or pex Constructed of DZR brass Certified to 200 PSI & 200 degrees fahrenheit Design certified to ASSE1061 NSF61 standards Meets UPC, IPC & CUPC requirements