Cash Acme 3/4 Inch Tank Booster Water Heater with Thermostatic Mixing Valve, Temperature Gauge, Braided Hose, Domestic and Commercial Application, PEX Pipe, PE-RT, CPVC, Copper, 24644 - Amazon.com
Rheem RTEX-AB Water Heater Booster - Amazon.com
Eemax® TankBuddy® Water Heater Booster at Menards®