American Water Heater, GU61-50T40R, Proline Master, 50 Gallon Ultra-Low NOx Natural Gas Water Heater, 8 Year Warranty, Intelligent Control Logic, Green Choice Gas Burner, Coregard Anode Rod, Blue Diamond Glass Coating, Self Cleaning , 450 , 40,000 BTUs, Water Connection on Top, Height 57-1/4", Diameter 20", Vent Size 3" to 4"