Personalized Basketball 1st Birthday 1 Year Old T-Shirt. Basketball sports ball with number 1 for a little boy celebrating his first birthday. Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.