B10, battery fence charger, 0.1 joules stored energy, for multi wire portable fences up to 6 acres, 3/5 mile, clips on to polywire, polytape or galvanized wire, uses 6 super heavy duty long life "d" cell, up to 3 months battery life with the latest generation alkaline batteries, built in fence pulse indicator light flashes at each pulse, pulse rate slows to conserve battery life as batteries run down.