1 dozen baseballs Solid Cork Composition Core Duracover Diamond Seam (raised seam) design for feel and control DBX is a great practice baseball Diamond DBX Official League Baseballs...Out Of The Park Performance! Duracover synthetic cover practice baseballs are the best practice baseballs on the market. Feels better to the grip and lasts longer than most all baseballs. * Solid cork composition core * Diamond Seam (raised seam) design for feel and control * Available in Dozen quantities Diamond...Simply The Best!