I have 5 dogs of my own and use this system to walk them all at the same time or walk any number of them. I also use it for my Australian Shepherd/Border Collie when we go on runs or when I bike and she runs, depending on how lazy I am that day! I would like to see stronger clips that can handle a dog that suddenly lunges at that squirrel or that dog. I don't recommend this system for dogs that haven't been trained to walk loose on a leash and to focus on their handler.