Description: Function: Magnesium anode rod protects your RV water heater from corrosion, extending its service life. Material: Made of environmental protection magnesium alloy. Magnesium structure is softer and absorbent than steel. Application: magnesium rod is mainly used for water heater, heat exchanger, evaporator, boiler, etc. Spare parts: great replacement for the old one. Check regularly, rods should be replaced every year or when corrosion has eaten away about 75% of the rod weight. Easy to use: measures approximately 13 x 11 5mm/0.5 x 4.5 inch, uses 1/2 inch NPT thread, easy to install. Specification: Material: Alloy Magnesium Color: Silver Size (LxL): Approx 13 x 11 5mm/0.5 x 4.5 inch Pipe Thread: 1/2 inch NPTI Thread Quantity: 2pcs/pack Package include: 2pcs x magnesium anode rod 1pc x tape Note: 1. Due to the light and screen difference, the item's color may be slightly different from the pictures.2. Please allow 1-2 cm differences due to manual measurement.