Viessmann Manufacturing® Indirect Water Heater, 42 gal Tank, 300 V, 300 W Power, 91 to 175 gph Flow Rate, 3/4 in MNPT Gas Connection, 3/4 in MNPT Water Connection, 264 to 472 gph Recovery Rate, 220 psig Pressure, Stainless Steel, 23 in L x 23-3/4 in W