The Rheem SP20865 ProtectionPlusTM Warranty Extension Kit adds 4 years of warranty protection to a Rheem residential water heater. It includes a magnesium anode rod, a heat trap nipple with a reducer bushing, and a Protection Plus label. This kit is designed to extend the limited tank warranty of Rheem water heaters, typically from 6 to 10 years or 8 to 12 years, depending on the original warranty.