The Rheem AP11525T-2 Anode Rod is designed to protect your water heater from corrosion. With a diameter of 0.840 inches and a length of 39-3/8 inches, this magnesium anode rod effectively extends the life of your water heater by preventing rust and degradation. It is compatible with various water heater models and is essential for maintaining optimal performance. The magnesium material ensures superior protection compared to aluminum or zinc alternatives, making it a reliable choice for homeowners. Regular replacement of the anode rod is recommended to ensure your water heater operates efficiently and lasts longer.