2 Pack 1/2 inch NPT RV Water Heater Anode Rod with Tape – Magnesium Anode Rod for Heaters 11553. Made from high-quality magnesium material, this anode rod attracts oxidizing substances and contaminants in the water through electrolysis, helping prevent rust in the metal water tank and extending the life of your RV water heater. These magnesium anode rods are more effective than aluminum rods at attracting corrosive elements, providing superior protection against corrosion and helping prolong the lifespan of your water heater. Extends the life of a water heater by sacrificing itself to corrosion. If the anode rod becomes depleted or fully decayed, the water heater tank may begin to rust, crack, fail, and leak. Each magnesium anode rod measures 4.5 inches long (115mm), 0.5 inch in diameter (13mm), with 1/2 inch NPT threads. Designed to fit compatible RV water heaters. To drain the tank, unscrew the anode rod. If the rod is significantly corroded or worn, replace it with a new one. It is recommended to keep a spare anode rod on hand in your RV. Color: Silver. Material: Magnesium Alloy + Steel. Note: Appearance and color may vary slightly between batches, but this does not affect performance. Package Contents: 2 x RV Magnesium Anode Rods, 1 x Thread Seal Tape (color may vary). Note: Light reflection and display settings may cause slight color variations between the image and the actual item. Measurement error allowed is +/- 1-3 cm.