The mesh back panel is particularly well suited for ventilation as your body heats up and the fit has been engineered to maximize comfort and efficiency. This jersey is everything you need and nothing you don't.Renew Series Main Body. Moisture-Wicking Fabric. Main Body: 100% Recycled Polyester Bluesign-Approved Fabric. Mesh Ventilation Back Panel: 100% Polyester. 3 Rear Cargo Pockets. Full-Length Front Zipper with Zipper Guard. Fit: Fitted.