YeuriSafety Material: These RV water heater anode rods are made of 99.8% extra durable magnesium. Non-toxic, harmless to human body. Compared to aluminum (a common material for RV water heater anode rods), it is safer, and magnesium is not potentially hazardous. They are safe for you and your family. Compatibility: These magnesium anode rods are 9.25 inches long, come with 3/4 inch NPT threads, and are compatible with Mor-Flo and water tanks. The rods use a 1 1/16" socket. Not compatible with 1/2" thread or 4" long rod. Please Note: Replacing the anode rod before the water heater works will slow down the corrosion inside the water tank and greatly extend the life of the water heater, sometimes even doubling. The anode rods should be replaced regularly in 6 months to 1 year, keep a spare in your RV. Quantity: 2pcs Color: Silver