All COO BABY onesie footie sleeper pajamas are made from a super soft, breathable, and stretchy bamboo viscose and spandex combination. Bamboo is naturally moisture wicking and is great for regulating temperatures in both warm and cold environments! The onesie romper also includes optional hand cuffs, feet grippers to prevent slipping, and a two way zipper / inverted zipper / double zipper for easy diaper changes. Just unzip from the bottom while the top stays on - keeping your infant warm and relaxed. We offer classic solid colors for those wanting to keep things minimalistic - which also makes them easy hand-me-downs for future siblings and great baby shower gifts! Please Note: These do have a slim and snug fit to comply with safety standards. Please keep that in mind while selecting your size.