American Standard R520R520 Ceratherm Rough Valve Body with 1/2-Inch NPT Inlets/Outlets, 7.2 GPM at 40 PSI Bath / shower accessory Brass thermostatic valve body Ceramic disc valves assures a lifetime of smooth handle operation and drip-free performance Hot limit safety stop protects from accidental scalding 1/2-inch NPT inlets/outlets