Recently Upgraded To Version 21.0 Funny 21st Birthday 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 Computer nerd humor 21st birthday gift idea Funny gift for any coder or gamer turning 21 years old Lightweight, Classic fit, Double-needle sleeve and bottom hem