Reliance 6-50-UNBRT 400 Natural Gas Ultra Low Nox Water Heater is a reliable and efficient choice for your water heating needs. It features a 50 gallon capacity and runs on natural gas, offering ultra low nox emissions. With a powerful 40000 BTU output, it ensures quick and efficient heating. The draft diverter outlet size is 3 inches, with an integrated adapter for a 4 inch vent option.SpecificationsCapacity: 50 gallonEnergy Factor: 0.60Recovery at 90 degrees rise-gallons/hours: 43First Hour Rating: 91Insulation: 1 inchT&P Valve: Factory installedGas Control System: Advanced with internal microprocessorValve Power Source: Self powered with thermopileDimension: 26\" L x 23\" W x 60.38\" HWeight: 168 lbsFeatures50 gallon capacityNatural gas ultra low nox water heater40000 BTU outputDraft diverter outlet size 3 in. With integrated adapter for 4 in. vent option0.60 energy factorRecovery at 90 degrees rise-gallons/hours 43First hour rating 911 in. insulationFactory installed T&P valveNew advanced gas control system incorporates an internal microprocessor providing enhanced operating parameters & a tighter differential for precise sensing & faster heating response to optimize performanceValve is self powered uses a thermopile to generate the power needed to operate valve & incorporates self diagnostics & monitoring- SKU: TRVAL70206