Camco's 4500W/240V screw-in foldback type Ultra low watt density water heater elements are better suited for areas with problem water (hard water, lime, etc.) Premium Ultra LWD Lime Life elements carry a limited 5 year warranty. The Ultra LWD of this element helps prevent lime deposits and the high performance nickel-chromium stainless steel alloy sheath gives it additional strength to resist dry firing. The combined effect make the element better suited for use in areas with problem or intermittent water supply. Screw-in type elements are universal replacement parts that fit most models of American, AO Smith, Bradford White, Craftmaster (prior to 1991), GE, GS Wood (certain models), Kenmore, Lochinvar, Maytag, Mor-Flo, Reliance, Rheem, Richmond, Rudd, Sears, State, Whirlpool and most water heaters manufactured after 1994. The replacement element must be the same voltage and wattage as the element being replaced. Never exceed the nameplate rating on the water heater.