40 Gallon, Natural Gas Water Heater, 40,000 BTU's, 2" Insulation, First Hour Rating 70, 41 GPH. For Installations From Sea Level To 10,100', R Value 16.00, EF Rating .62, Draft Diverter Outlet Size 3" With Integrated Adapter For 4" Vent Option, Factory Installed T & P Valve, Next Generation FVIR Approved, Stainless Steel Flame Arrestor, Air Intake Surrounds The Entire Base Of The Water Heater, Door Mounted Manual Reset TCO, Not For Use In Mobile/Manufactured Homes Unit Dimensions 61-3/4"H x 20"D, 6 Year Tank & Parts Warranty, Models Built After 4-1-2011 Have Self Powered Honeywell Millivolt Generator Gas Control Valve.