Invisible dog fences are really plain. The wire moves a signal broadcasted from a tiny unit. The dog wears a unique collar that receives an electrical shock if it approaches the wire or goes across the fence. More precisely, these electrical signals are mostly zoned. When the dog crosses a warning zone anywhere close to the wire, it is going to hear a warning audio signal originating from the collar. If it gets even closer, it will receive a buzz from a small electrical impulse