I have a 9 going on 10 month old, 100 lb German Shepherd. Very active and in shape, huge puppy. He would normally DESTROY a tennis ball within a few hours to a day with his constant chewing and playing with the ball. I considered this and decided to buy it. I bought the Medium size because I still wanted him to be able to chew it. The large size is definitely big (I went to petsmart to check out the sizes but purchased here, price is waaay better!). I tested which size he'd like and he played with the Medium size more since he was able to chew it. He can't choke on it since its not too small for him. He's been playing with it for a few months now and its still intact. Less bouncy than when we first got it, still bouncy of course, but he is a huge puppy and chews on it ALOT. It is the only toy he has not gotten tired of! I also gave the same size ball to my boyfriend's new dog (Husky 2 months old) and he loves it chews on it as well and it squeaks the same way as with my GSD. For our dogs, its the perfect option and the Medium is the perfect sizing. Its a little smaller than a traditional tennis ball, but the closest size out of all the other size of the Kong Squeakier Balls.