These infant size dividers come with 5 each of Newborn, 3Mo, 6Mo, 9Mo, 12Mo, 18Mo, 24Mo, 2T, 3T, 4T. The rack markers are 3.25 inches in diameter. These infant size dividers are made of a white break resistant plastic. The rack markers have black imprint on both side. These infant size dividers work on round apparel racks.