50 gallon, natural gas water heater, 40,000 btu's, 2" insulation, for installations from sea level to 10,100 ', .62 energy factor, recovery at a 90 rise-gallons/ hours 41, first hour rating 88, draft diverter outlet size 3" with integrated adapter for 4" vent option, t & p valve, pex lined heat trap heat trap nipples, pex dip tube, glass lined tank, dual mag anodes, fvir approved, stainless steel flame arrestor, air intake surrounds the entire base of heater, door mounted manual reset tco , unit dimensions 60-7/5"h x 22"d, 12 year tank & parts warranty, not for use in mobile/manufactured homes, will void warrnaty, have self powered honeywell millivolt generator gas control valve, meets new naeca 2015 efficiency standards.