Lochinvar® Copper-Fin II® Commercial Gas Boiler, Heavy Duty, Natural Gas, Net IBR Rating: 295 MBtu/hr, 399 MBtu/hr Input, 2 in NPT, 399 MBtu/hr DOE, 0.85 AFUE, Horizontal/Vertical Vent, 6 in Vent Size, 31-1/2 in H x 37-3/4 in W x 22-1/4 in D