Champro Ace Sleeveless Baseball Jersey The Ace sleeveless baseball jersey from Champro Sports is made from 100% polyester warp-knit fabric and is pro-weighted and highly resistant. It features a 6 button sleevelesss design for comfort in all weather conditions. Product Features: 100% polyester Pro-Warp material Abrasion Resistant 6 Button Front Sleeveless design Serged bottom Item#BS16