0.1 Joules stored energy. For multi wire portable fences up to 1km (3/5 mile). Fully modular. Clips on to Gallagher Poly Wire, Poly Tape or galvanised wire. Batteries: 6 Super Heavy Duty Long Life “D” Cell. Battery life: up to 3 months 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. Can be used with external 12 volt battery using B10 12V Battery Adaptor Kit (G521).