By the way, there is something to be said about the "tingle" versus "jolt" of these small systems. Often people touch them and think that the tingle is nothing. They can hold their hand there and, while not comfortable, they can tolerate it. But, they forget that they are standing there with shoes on, which insulates them considerably. The animals are not insulated and have direct connection to the earth with 4 feet. I learned this lesson the hard way one day. I was leaning with my hand on a metal post that was going into the ground, and touched the fence wire with my other hand without thinking. The shock felt like a punch from Mike Tyson, and was not something I would subject myself to voluntarily, like I normally do when I test the fence with my hand, with shoes on.