Our infant rompers come in four sizes, from 0-3 months, 3-6 months, 6-9 months, and 9-12 months. Once your kiddo graduates from those sizes, we have Rags for toddlers to preschoolers. For height, weight, and length measurements, check out our newborn and infant Rag rompers sizing chart. RAGS newborn rompers are made from stretchy-soft materials, so they are flexible for those growth spurts and in-between sizes. And if your baby has a little extra of those adorable baby rolls, that fabric stretch really helps!