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 Great novelty design and funny idea for the Electrical Engineer, Engineering professors and the students to raise a smile on everyone's face. Electrical Engineering Shirts Electrical Engineer Gifts Men Lightweight, Classic fit, Double-needle sleeve and bottom hem