Rheem UV99004 Flexible Aluminum Anode Rod with 0.75-Inch Diameter and 42-Inch Length For best results, use only Rheem replacement parts for repairing your Rheem Water Heater Anodic Material: Aluminum, Total Length (in.): 42, Rod Diameter (in.): 0.750 Hex Head Size (in.): 1-1/16, Thread Size - NPT (in.): 3/4, Resistored: No