Lands' End Men's Short Sleeve Mock Twist Active Performance Polo Shirt 100% polyester 100% polyester. Breathable mesh jersey has a cotton heather look. Flat overstitched seams for comfort. Side vents at hem for breathability. Antimicrobial finish helps keep fabric fresh. Fabric wicks moisture to help keep you dry and cool. Slimmer through the body, but not tight. Machine wash. Imported.