For use with your electric fence, this shocks through wet weeds and brush for livestock control in small to medium size pastures. The Solar Pak 6 is laser trimmed, computer precision, solid state circuitry provides reliable, powerful low impedance shock to end of fence. Uses free energy from the sun for maximum shock – day or night. Eliminates need for expensive battery replacement or inconvenient recharging. At a glance built-in performance meter shows you the fence condition – good, marginal or bad. While reaching maximum power in direct sunlight, battery will charge even on cloudy days, and will operate for 21 days in total darkness when fully charged.