Personalized Nuclear Genius Newborn Layette. Nuclear Engineering Genius over a radioactive symbol is a humorous gift design for engineers and students at back to school, birthdays, holidays and graduation. 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