A.O. Smith ENS-50 ProMax Short Electric Water Heater, 50 gal Permaglas glass coating protects steel tank from corrosion and maximizes tank life Dynaclean diffuser dip tube helps reduce lime and sediment buildup while maximizing hot water output; made from long-lasting PEX cross-linked polymer CoreGard anode rode aluminum anode with stainless steel core protects tank against corrosion longer than ordinary steel anodes Durable, tamper-resistant brass drain valve Meets all current regulations set forth by the National Appliance Energy Conservation Act (NAECA)