I was skeptical and really didn't think it would work. After installing the boundary wire we had some difficulty in adjusting the collar. The first step instructs you to "remove the battery". That totally made the following steps nonsense. However, I contacted customer service and received the instructions that I needed. The support agent agreed that there was a problem with the manual and hopefully they will get that fixed. Now to the effectiveness of the boundary wire. It only took my German Sheppard 3 days to respect the boundaries. She "jumped" the "fence" one time while chasing a squirrel. She received the correction and then was afraid to return back in to the yard. I solved that problem by driving the van out of the yard and she came back in with the van. (She doesn't get shocked while in a vehicle). So now it is a pleasure to be able to allow her freedom from the leash and to be outside (she has an acre or more to run in).