Personalized Mechanical Genius Youth T-Shirt. Mechanical Genius text with a wrench is a humorous gift design for mechanics and vo-tech students at back to school, 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.