This is a great idea for anyone with a dog who loves to fetch.  The medium size allows you to throw a standard tennis ball as well as any of the other medium balls from Chuckit.  You can throw the balls very far with little effort and without getting your hands slimy form dog drool after a long day of fetch.  You don't even have to stoop to pick up the ball.  My dogs drop their balls on command (most of the time) so I just pick it up and re-Chuckit!  It's easy to use and very fun.  I've only had it for about a week so I'm not sure how it's going to hold up, but it seems pretty sturdy.