"made from an all-natural viscose bamboo blend, this fabric will keep baby cool yet cozy at the same time -- yep, it’s temperature regulating! The silky-smooth fabric is soft, breathable and comfortable, making it the perfect choice for the most sensitive baby skin. Two-way ykk zippers Foldover mittens on newborn and 0-3 month sizing Foot grips on 6 month + sizing Ankle elastic keeps little feet in place Zipper garage at neckline keeps zipper from rubbing against baby’s neck Zipper lining prevents direct contact from zipper to baby’s tummy [no interfering with those fresh belly buttons] Tag-free neckline Machine wash cold, tumble dry low heat"