My puppy just recently turned 4 months and he LOVES exploring his surroundings. The bad part is I live right next to a busy highway and do not have a fence. We have two other dogs that know not go get in the road so we've never had to deal with this issue before. He also does not listen whatsoever, he does, he just has selective hearing and likes to be a drama queen. I've heard of some people that have an invisible fence with larger dog breeds that don't even mind the fence and wondered if some of your german shepherds stay inside it or not and also what brands you guys prefer. Thanks!