Selling a never used underground radio fence, made by Pet Guardian. Comes with lots of transmitter wire, the neck collar, flags, instructions, box, batteries, etc. I have tested in to ensure its working, but it has never been installed or used. Utilizes a small electronic "correction" to the animal when too close to the "fence", also has warning beeps. Retails for ~$200 in stores, asking $100 firm. Works great!