Green 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/J DynaClean diffuser dip tube helps reduce lime and sediment buildup, maximizes hot water output and is made from long lasting PEX cross-linked polymer The internal microprocessor provides enhanced operating parameters and tighter differentials for precise sensing and faster heating response to optimize performance CSA certified and ASME rated T&P relief valve Push button Piezo ignitor makes lighting the pilot fast and easy with one-hand push button spark ignition Heat trap nipples are factory installed Core Gard anode rods have a stainless steel core that extends the life of the anode rod allowing superior tank protection far longer than standard anode rods Blue Diamond glass coating provides superior corrosion resistance compared to the industry standard glass lining Enhanced flow brass drain valve which is standard on our residential water heaters, have a solid brass, tamper resistant, enhanced flow, ball type, drain valve