What is the double loop layout and why do I need to do it?

A double loop is a type of wire layout which gives you the option to establish a boundary when you do not want to contain your whole property. In the double loop layout, you run the wire from your transmitter and around the yard. Once the wire reaches the opposite side of the yard from the transmitter, the wire needs to make a U-turn and follow the same path at least 5 feet away from itself as it goes back into the transmitter.