DVUG62-50T38-NV American Water Heaters 50 Gallon Ultra-Low NOx Direct Vent Natural Gas Water Heater6-year limited Tank warranty, 6-year parts warranty for Residential applicationsFlammable Vapor Resistant/Direct Vent Sealed Combustion System-Thru-the-wall/thru-the-roof venting of combustion productsDurable, Ultra-Low NOx Burner ConstructionGreen Choice® Gas Burner -Patented eco-friendly burner design reduces NOx emissions by up to 33% and complies with Low-NOx emission requirements of less than 40 ng/JCoregard™ Anode Rod - Our anode rods have a stainless steel core that extends the life of the anode rod allowing superior tank protection far longer than standard anode rodsBlue Diamond® Glass Coating - Provides superior corrosion resistance compared to industry standard glass lining