I bought this because my dog is a heavy chewer and thought it would take her a while to chew through it, but she had easily chewed about half of the ball within twenty minutes until I took it away. I didn't realize the ball was hollow, either. I think that's the main reason she could chew it down so quickly. She seemed to like it, though.
Do not buy this product if your dog is a destructive, heavy chewer! The ball is essentially hollow, and once it is chipped or broken, it can be easily destroyed in seconds. My cocker spaniel had it halfway eaten within half an hour. This compressed rawhide is supposed to stand up to heavy, aggressive chewers. This is not the case at all!