Designed as a single size to fit toddlers aged from 1 year to 3+ years old, you won’t need to buy a new one each time you child has a growth spurt. This uniquely designed onesie features a full inner leg zipper for easy nappy changes without opening the entire suit and clever fold over cuffs on the hands and feet so your toddler can safely walk and play with them open and be snuggly warm all night when they are folded closed.