100305721 a.o. smith product preservers powered anode rod system product preserver the product preservers powered anode system is an ideal solution for eliminating smelly water caused by sacrificial magnesium anodes or to replace aluminum anodes where aluminum hydroxide is a problem. the system is also great for new residential gas or electric 30-50 gallon water heater installations providing protection for years with virtually no maintenance required. protect your investment with a permanent anode rod made of titanium and mixed metal oxide that will never be depleted unlike traditional sacrificial anodes. this latest technology allows the system to quickly adjust to local water conditions providing the precise amount of current for the best protection of the water heater tank. protection is maintained as long as the control module remains connected to a power source and continually adjusts the amount of protection needed. additional features include a built-in led fault light and audible alarm that provide peace of mind knowing the system is working properly.