This simple little denim diaper cover is perfect for your baby boy or baby girl with any outfit. It features elasticized leg openings and an elasticized waist. NOTE: Diaper covers are sized to fit over diapers so are typically a little larger fit than you might expect from non-diaper cover panties. Typically, NB should fit birth to 3 months, SMALL should fit 3 to 6 months, MEDIUM should fit 9 to 12 months, LARGE will fit like 18 months, and XL will fit like 24 months. If you are looking for larger sizes, please look for them in the panties section of Tom and Jerry"s Children"s Clothing Store for toddlers and older children.