PRICES MAY VARY. Solid colors: 100% Cotton; Heather Grey: 90% Cotton, 10% Polyester; All Other Heathers: 50% Cotton, 50% Polyester Imported Pull On closure Machine Wash Biomechanical and Bioelctronics Representation of Human Heart Connected with Circuits Great Shirt for Electronics Engineers, Computer Engineers, Cyber Enthusiasts, Computer and Electronics Geeks Lightweight, Classic fit, Double-needle sleeve and bottom hem