We liked how strong the ball was and how bouncy and light. We use the balls for dog exercise hitting them over the paddock with a tennis racquet. Previously we were unable to find a ball that didn't get chewed up in the process, sometimes on the first use. We have used the balls every day since first discovering them around a month ago and they are in perfect condition although the dogs chew them all the time. We have found though, that both the medium & large size dog prefer the small size ball rather than the medium size one.