NTI Indirect Water Heater, Series: S Series, 333 MBtu/hr Heating, 120 gal Tank, 20 gpm, 3/4 in Water Connection, 389 gal at 140 deg F Recovery, 150 psi, 190 deg F Tank/210 deg F Boiler, Ultra Low Nox: No, 444 Stainless Steel, 28-7/8 in Dia x 64-3/4 in H