Personalized Las Vegas 21st Birthday Long Sleeve T-Shirt. 21st birthday Long Sleeve T-Shirt - Charcoal with Las Vegas welcome sign that says IT'S MY FABULOUS TWENTY-FIRST BIRTHDAY. Fun and unique for her very special birthday. 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