Pool Tool Inc. 104R-KIT, Inline Anti-Electrolysis Zinc Anode Replacement KitCondition:* New Surplus Stock, No OEM Packaging. As Pictured.Additional Notes:* Pool Tool Zinc Anode* The Zinc Anode Will Sacrifice Itself And Corrode Before All Other Metals In The Pool.* In doing so, the anode protects other metal parts from galvanic corrosion.* The Zinc Anode will need to be replaced approximately every 3 years or when it is 0.5 its original size. Pool Tool Inc. 104R-KIT