Parmak, Solar-Pak, Electric Fencer, With Sealed 6-Volt Gel Battery, America's First Solar-Powered Electric Fencer Is Now Equipped With The Lastest State-Of-The-Art Solar Panel, Increased Output, Longer Life, Solar-Pak Eliminates The Need Of Expensive Battery Replacement Or Inconvenient Recharging, For The First Time You Can Have Power Line Convenience In A Battery Fencer, Solar-Pak Will Operate For 21 Days In Total Darkness, Weatherproof, Outdoor Model, Charges Up To 25 Miles Of Fence, UL Listed.