Personalized Submarine 6th Birthday Newborn Layette. THINGS ARE LOOKING UP 6th birthday Newborn Layette - White with big number 6, colorful submarine, little deep sea explorer in the porthole and bright fish with bubbles. 100% combed ringspun cotton 5.8 ounce 1×1 baby rib sleeper. 3/8" flatlock binding at envelope neck and cuffs. Back sleeve flap to protect hands. Elastic opening at bottom. Infant: 0-3 Months