Personalized Mechanical Engineer Gear Sketch Youth T-Shirt. Mechanical Engineer text across a gray sketch of a gear is a unique engineering design for engineers and engineering students at birthdays, holidays and graduation. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.