Electronic Dog Fence System -Invisible Electric Wireless TP16 Containment CollarThis hidden TP16 fencing system is a cost efficient pet friendly containment systems. A buried wire transmits a harmless radio signal. When your dog approaches the boundary (within approximately 2 metres), the signal causes the dog collars receiver to deliver a warning beep first. If the dog continues further, the system will issue stronger beeps and until your dog returns to within the boundary you have set up. Specifications and Features: Pulsed