Having watched two other leashes fail after about two years of use on each, I am confident this one will not experience a similar failure. We have an energetic, strong 85-pound black lab, and she walks me 4-6 miles every day. Our other leashes both failed in precisely the same way: the flange/swivel between the clasp and the strap simply snapped. This is an insidious failure, the timing of which is difficult to predict. It usually happens when the dog gets excited and provides a significant sharp tug on the leash. Thankfully, in both cases our dog stayed out of trouble. Now, with the ball-bearing endowed Gear Fur leash we don't have to worry about repeating the unnerving experience of watching our dog lunge at something only to see the leash break at the critical moment.