Syttende Mai Norwegian Flag Holiday T-Shirt Solid colors: 100% Cotton; Heather Grey: 90% Cotton, 10% Polyester; All Other Heathers: 50% Cotton, 50% Polyester Imported Machine wash cold with like colors, dry low heat 17th of May Holiday Shirt. Perfect to celebrate at the parade and show off your Norwegian heritage and love for Norway! Lightweight, Classic fit, Double-needle sleeve and bottom hem