Personalized Santa Hat Brain Long Sleeve T-Shirt. A happy brain wearing a Santa hat is a humorous winter holiday gift design for psychologists, neuroscientist, neurologists, neurosurgeons and medical students. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL