(Tru-Test) The Speedrite AN20 Electric Fence Charger is designed specifically for strip grazing, horse corral kits and small fence lines. Electrical components are protected inside a rugged enclosure, providing reliability in the toughest conditions. Reinforced lid catch secures the charger to fence wire. The Speedrite AN20 Electric Fence Charger operates on (2) D-cell batteries. Up to 35 days of battery life.