The Amazing Baby premium cotton knit sleeping sack is perfect when baby is ready to graduate from swaddling. Features a 2-way zipper which zips down from the top, making it easy to place baby into sack, and also zips up from the bottom, keeping baby snugly warm during diaper changes. So easy! Exclusive design for Amazon by artist and mom, Lynette Damir. This cotton knit wearable blanket is a designed for moderate to warmer environnments. Small fits up to 28". Medium fits up to 32". Large fits up to 35". Coordinates with a variety of our quality baby essentials. Machine washable. Designed and manufactured by SwaddleDesigns exclusively for Amazon.