Noritz® Tankless Water Heater, High Efficiency, Series: NRC661, Natural Gas, 1/2 in Gas Connection, Direct Electronic Ignition, Direct Vent, 3 in Vent, Condensing/Non condensing: Condensing, 0.5 to 6.6 gpm, Energy Factor: 0.89, Copper/Stainless Steel Heating Element, Wall Hung Mount, 3/4 in Water Connection, 15 to 150 psi, 100 to 140 deg F, Ultra Low Nox: No, Indoor/Outdoor: Indoor, Beige, 20.5 in H x 13.8 in W x 6.7 in D, Commercial/Residential/Dual: Residential