Personalized Rock On Infant Romper. Rock On. A rock sits atop the word on is a humorous twist to a common phrase. Make your favorite rockers and music lovers smile with a unique gift at birthdays, holidays, graduations and back to school. Meet your new favorite outfit! Keep dressing simple with this one piece, lap shoulder t-romper. Super soft and perfect for baby's sensitive skin. 5.5 oz. 100% combed ringspun cotton premium jersey (CVC Colors are 60/40; Heather is 90/10 combed ringspun cotton/polyester)