I do a lot of work with rescue. We often get puppies who are notorious for chewing the crap out of everything. I figured that these would be good for them. Unfortunately, the claim that they are durable and for aggressive chewers isn't quiet as accurate as I had hoped. They were fine for some of the smaller breeds and some of the younger ones. The older puppies and ones from the larger breed mixes had a much easier time pulling them apart. These are great from small breed puppies but I wouldn't recommend them for larger breeds. I would also be careful if you have a number of different sized dogs in your house. I have a smaller breed that would probably enjoy one since he isn't that aggressive with chewing. But, I can't risk giving him one because I also have a large breed dog that one of these balls could easily become a chocking hazard for if he got ahold of one.