Personalized Submarine 4th Birthday Men's V-Neck T-Shirt. THINGS ARE LOOKING UP 4th birthday Men's V-Neck T-Shirt - White with big number 4, colorful submarine, little deep sea explorer in the porthole and bright fish with bubbles. 4.7 oz., 100% pre-shrunk cotton Narrow, set-in 1x1 mitered V-neck collar Shoulder-to-shoulder taping Double-needle stitched sleeves and bottom hem