Not just twisted wire, twisted Ultra Wire. This is the same custom engineered Ultra Wire included with the HC-8000 Ultra Electronic Dog Fence and twisted for use in canceling the signal field in areas where you want your dog to be allowed to cross. Twisted wire cancels the signal field and does not trigger your dog's receiver collar. You need twisted wire to connect your boundary loop to the transmitter and to create safe zones where your dog can safely cross buried wire. This allows you to create smaller boundaries within your yard to keep your pet away from the pool, flower beds, and other off limit areas. You get 100 feet of pre-twisted Ultra-Wire.
Here are some helpful tips for using Twisted Ultra Wire in your boundary field:
Your field configuration must make a continuous loop beginning at the "Red" terminal of the base station transmitter and ending at the "Black" terminal. You use twisted wire to cancel the field in areas that you wish to allow your pet to cross. This is a simple process, but it can be a little tricky. You need to make sure that each of the twisted wires is one leg of the continuous loop otherwise the field won't cancel. Take a look at the examples below:

Example 1 Larger View.

Example
2 Larger View.

Example
3 Larger View.