Features exclusive built-in performance meter. Shocks through wet weeds and brush. Laser trimmed, computer precision, solid state circuitry provides reliable, low impedance shock to end of fence. For livestock control in small to medium size pastures. At a glance built-in performance meter shows you the fence condition. Good, marginal or bad. Will operate for 21 days in total darkness on a fully charged battery. Totally weatherproof for outdoor use. Comes complete with sealed 6 V gel battery. Ready for use. Charges up to 25 miles of fence.