Electric Stubborn Underground 2 BIG Dog Fence 1.2 Acre Dog Fence Systems Kit Transmitter with wire break alarm,Covers up to 10 acres with additional wire Battery for the collar 300 metres 1.5mm of solid copper-alloy core boundary wire (covers 1.2 acres) Fuse Protection-The fence transmitter is equipped with a 250 volt, 0.5amp fuse to protect the unit's electronic circuitry from electrical power surges. Variable Field Width Control- Allows you to precisely control the width of the signal field