NIKE Hypercool Fitted Short Sleeve Crew Dri-FIT Max fabric wicks sweat to keep you drier, faster. Mesh fabric adds extreme ventilation in high-heat zones. Warp-knit back creates durable mesh that resists tears. Fitted design provides freedom of movement; Flatlock seams move comfortably against your skin Body: 91% Polyester 9% Spandex; Back Panels: 100% Polyester