Camco’s 4500W/240V Screw-In, Ultra-Low Watt Density Water Heater Element is a universal replacement for the Rheem manufactured Marathon water heaters. This upper replacement element is constructed with a brass bushing with copper sheath and contains a thermal fuse to protect the water heater from damage due to a dry-fired element. The replacement element must be the same voltage and wattage as the element being replaced. Never exceed the nameplate rating on the water heater. Minimum tank size: 30 gallons. Sheath length: 14.1-inches. The Marathon ultra-low watt density element carries a 5-year limited warranty.