Personalized Caffeine Powers Activate Long Sleeve T-Shirt. Caffeine Powers Activate! If your super powers take a cup or two (or five) of coffee to show up, then you have caffeine powers! Funny gift for any coffee lover. 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