Lochinvar® Copper-Fin II® Gas Water Heater, High Efficiency, Series: CFN, Natural Gas, 399000 Btu/hr Input, 2 in NPT Water, Hot Surface Ignition, Aire-Lock Direct Vent, 6 in Vent, Ultra Low NOx: No, 22-1/4 in W x 37-3/4 in D x 31-1/2 in H, Commercial/Residential/Dual: Commercial