Usage Tips:Made using high-quality magnesium-material. magnesium-rod oxidizing substances and all the contaminants in the water towards itself by electrolys, preventing the water tank from rusting in the metal water tank, ensuring your RV water heater lasting use. These water heater magnesium anode rods work aluminum ones in attracting , protecting your water heater tank from being corroded and prolonging life span. Extends the life of a water heater by attracting in the water. If the anode rod is depleted and fully decayed, the water heater will begins to rust, then crack, fail and leak. These magnesium anode rods are 4.5inch long/115mm, 0.5 inch diameter/13mm, 1/2inch threads,fits for . Use with: For . Unscrew the anode rod to drain the tank. If the rod is mostly eaten , replace with a one. Always keep a spare in your RV. Colour:silver Material:Magnesium Alloy + Steel Different batches, the appearance and color of the anode rod may be different from the picture, which does not affect Package Contents: 2 x RV magnesium anode rods 1 x tape (the color of the tape is random, 't accept the specified color) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.