AO Smith® Tankless Water Heater, High Efficiency, Series: CT-199, 199000 Btu/hr Heating, Natural Gas Fuel, 3/4 in NPT Gas Connection, Electronic Spark Ignition, Direct/Power Vent, 3 or 4 in Vent, Condensing Condensing/Non Condensing, 10 gpm Flow Rate, 0.93, 3/4 in NPT Water Connection, 15 to 150 psi Pressure, Yes Ultra Low NOx, Indoor Indoor/Outdoor, 17-3/4 in W x 11-1/4 in D x 23-5/8 in H, Commercial