Personalized Nuclear Ornaments Long Sleeve T-Shirt. A green tree with radioactive symbols instead of ornaments is a unique gift design for college students, physicists, environmentalists, nuclear engineers and workers at birthdays and holidays. 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