Comes with a personal pump. We love versatile fitness tools, especially ones you can fold up and fit in your pocket, like the mini exericse ball. This must-have ball inflates easily with a straw to a diameter of seven to 10 inches depending on the desired firmness. You can easily deflate the ball too. And once flat, it's easy to pack, making it perfect for traveling.There are so many exercises you can do with these miniballs, but here are three of our favorite moves.