Good idea to do your research first. Electronic dog fences are not a physical barrier, they are a training and reinforcement tool. The initial training is all-important, and long-term, consistent reinforcement is essential. Also, your dogs will not be protected from the outside — other animals or people can still cross into your yard and threaten your dogs’ safety. Electronic fences depend on gadgets and gadgets are prone to occasional failure (not to mention human error). Personally, I do not leave my dog outside protected only by an electronic fence unless I am at home. That said, electronic fences perform very well within certain constraints.