NTI Boilers Watertube Boiler 94% AFUE 5:1 Turndown, 600k-Input, 564k-Gross Output, 380 lbs, Water Content-4 gallons, 2" FPT Heating Connections, 1" MPT Gas Connection, 4" Vent Size, Dimensions-47-1/2"D x17"W x37"H