This 26L Chuckit! Launcher came w/one ball... a little bigger than a regular tennis ball. I can now 'launch' a ball quite far and it also can be used to pick up the ball with a snap upon return... great! I tried using it with a regular size tennis ball it will throw it OK but not as good. Also it doesn't really grab a hold of it to pick one as easily. We go through lots of balls so wanted to check that out. So for now I bring that ball back inside when we are done with the launcher. I must say I really needed this... before my dog would either get hit by the thrown ball (he ran faster than I could throw) or would have to come back to where it landed... hehe. We have much more fun now!