Callaway Men's Big & Tall Golf Performance Short Sleeve Block Crew T-Shirt 92% Polyester, 8% Spandex Imported Opti-Dri: transfers moisture away from the body to aid in evaporation OptiShield: create a layer of protection from the sun's harmful ways, UPF 50 OptiStretch: interwoven layers of Spandex to ensure maximum range of motion so the garment moves with the golf swing Machine Wash Cold, Tumble Dry