For our dog we just got, we have tried a few different leashes, collars, and no pull harnesses. I heard about these on a forum and this was a night and day difference for leash training with my excited 6 month old shepherd. It’s stiffness lets you put a little down pressure on the lead to let the loop go totally slack. But when the dog pulls it cinches down nice, and loosens up easily when they ease up or get a correction. Well worth the money, a little tough on the hands when it’s cold so my wife doesn’t like it as much, but the kids do because she walks nicer,