This t shirt is inspired by those worn by everybody\'s favourite professor - Dr. Sheldon Cooper! The tee features a distressed, vintage-look print of the number 73 within a circle. As fans of The Big Bang Theory may know, 73 is the best number! Why? Because 73 is the 21st prime number, its mirror 37 is the 12th and its mirror 21 is the product of multiplying, hang on to your hats, 7 and 3. This is a 100% cotton t shirt, inspired by one worn by Sheldon (Jim Parsons), not official merchandise. #8ballbestseller Sustainability Message All 8Ball Originals garments are WRAP certified, REACH compliant and Fair Labor Association accredited. They are printed in UK using Oeka-Tex and GOTS certified water-based inks.