This energizer powers up to 110 mile or 650 acre of clean fence. Crafted from a rugged combination of tough, high-impact plastic for its outer casing and a built-in lightening diverter with the latest internal circuitry, this energizer is designed to last. The M1100 replaces Gallagher's trusted M1000 model with more power. The added power reserve in this unit has built-in technology that increases voltage output when fence conditions change.