Instant Fence by PetSafe is one of the easiest, and most effective invisible dog fences around. There are no underground wires or unattractive poles to install. You simply plug in the transmitter, put the receiver collar on your dog, and that's it.

When your dog reaches the boundary of the "fence" it receives a warning beep. If the dog goes beyond the boundary, it receives a mild electro-static pulse to remind it to return to the safe area.

Easy to install. Comes with a video to show you how to set up the instant fence. 6 programmable correction levels. Receiver collar is 100% waterproof. Works up to 180 feet diameter.