Invisable fencing do not work. I can not tell you how many dogs I have picked up running at large, with a invisable fence collar on. Wear a collar for a day, and see how it feels getting shocked, when getting to close to the fence. It is actually quite painful. Also, I know like you said there are different settings on the collars. The problem with this is that, alot of owners (once there pet gets through the fence) they will turn it up, in hopes of there pet not getting through a second time. (Actually one of our adoption staff put on a collar and turn it on the highest setting that they collar had, and it pretty much threw her out of her chair) Please think of another alternatlves.
Last edited by NoahGrey; May 12th, 2010 at 03:26 PM.