Eastbay Two-Button Mesh Baseball Jersey - Boys' Grade School Suit up in the Eastbay Mesh Short-Sleeve Two-Button Jersey. This 100% polyester mesh baseball jersey features moisture-management technology that wicks sweat away from your body, leaving you cool and dry during the pressure moments of the game. This jersey is great for customization and gives your team the winning look. Join the team with the Eastbay Mesh Short-Sleeve Two-Button Jersey. Imported.