Parmak, solar-pak, electric fencer, with sealed 6-volt gel battery, America's first solar-powered electric fencer is now equipped with the latest 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.