Baden Ballistic Leather Pitching Machine Baseballs are a genuine leather pitching machine ball. Featuring a flat Kevlar seam, synthetic blend windings, and a dura cork and rubber core so this ball maintains its shape longer than standard practice balls. It’s official size and weight and can be used in any pitching machine. These baseballs are perfect for indoor and outdoor practice alike – just toss them in your pitching machine and get ready to hit. These baseballs are sold as a five dozen package in an On Deck Sports Bucket with Padded Lid.