Personalized Ohm Mighty Dark Products Youth T-Shirt. Tickle the funny bone of your favorite science geek with this design for birthdays, holidays, back to school and graduations for your favorite scientist 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.