Series: TK-310C, 190000 Btu/hr Heating, Natural Gas, 3/4 in NPT Gas Connection, Electronic Ignition, Concentric Vent, 3 in, 5 in Vent, Condensing/Non Condensing: Non-Condensing, 8 gpm, 0.82, 3/4 in NPT Water Connection, 10.5 in WC, 35 deg F, Ultra Low NOx: Yes, Copper, Indoor/Outdoor: Indoor, 20-1/2 in H x 13-3/4 in W x 10-1/2 in D, Residential (Price subject to change without notice. Check stock before order)