Personalized Rocket 4th Birthday Women's V-Neck T-Shirt. Happy 4th Birthday! A rocket blasts off from an alien world with a giant 4 for the four year old's fourth birthday! 5.0 oz., 100% pre-shrunk cotton Athletic Heather is 90/10 cotton/polyester 1x1 rib collar with mitered v-neck Shoulder-to-shoulder taping Ladies' fit