I have two young boxers. My female weighs 65lbs and my male weighs 80lbs. They are both strong pullers on walks and have even pulled me down a few times. This harness the best harnesses I've purchased for my boxers. It doesn't hurt the dogs in anyway and very easy to use. It fits them great in the front, I've had other harnesses that just aren't made for "bully breeds" bodies and never fit the boxers properly on their front torso. When I use this harness, I attach my lease to the front D ring and that seems to work the best on walks and I can easily pull them away when them try to jump or someone or start pulling. I never walk them together b/c they are just too strong to be walked together by one person, but I walk them each one at a time and the harness is great and it gives me a lot of control.