AO Smith ProMax GPVT-50 Power Vent Tall Propane Gas Water Heater, 50 gal Exclusive 3-position rotatable blower outlet adds flexibility for an easy installation CoreGard exclusive aluminum anode rod has a stainless Steel core, which protects the tank against corrosion longer than ordinary mild Steel anodes Brass drain valve is more durable and tamper-resistant than an ordinary plastic drain valve, which contributes to improved safety and reliability Meet the september 2010 Energy Star EF requirement and may also qualify for local Utility and rebate programs Dynaclean II dip tube optimizes inlet water pressure to minimize cold water regions Within the tank, the self-cleaning action also reduces sediment accumulation on the bottom of the tank