This is our second pack, our first pack worked out so well during our last weekend backpacking trip that we got another pack so one of our other dogs can also carry some gear. Fits pretty securely, our dogs don't mind it even with some weight in the pockets. We've used it so far on our 100lb male Rottweiler, who has a pretty broad chest and he carried it for about 5hrs on two days without being bothered.