This is really interesting discussion ... I saw a video of a prong collar training and it was enunciated about 20 times that those collars OPEN immediately if any pull move is made and that dog can get loose if you accidentally pull on the leash too fast :rolffleyes: !!! So, how than they can "lock" 2 dogs and not make a automatic "release" :scared: or "choke" dogs to death ??? Really strange :rolffleyes: