30 gallon, natural gas, short, water heater, 35,500 btu's, 2" insulation, for installations from sea level to 10,100', .63 energy factor, recovery at a 90 rise-gallons/ hours 36, first hour rating 62, draft diverter outlet size: 3" with integrated adapter for 4" vent option, t & p relief valve, glass lined tank, anode rod, pex polymer lined heat trap nipples, pex dip tube, next generation fvir approved, stainless steel flame arrestor, air intake entire base of heater, door mounted manual reset temperature cut off, unit dimensions: 50"h x 20"d, 6 year tank & parts warranty, not for use in mobile/manufactured homes, will void warranty, self powered honeywell millivolt generator gas control valve, meets new naeca 2015 efficiency standards.