Hudson Baby safe sleep interlock cotton 100% cotton sleep sacks are a perfect safe sleep wearable blanket for your little one. Our sleep sack is designed sleeveless to prevent overheating and has a zipper closure for easy on and off dressing and night time diaper changes. Our sleep sacks are made with high quality cotton to keep baby feeling comfortable and cozy. Our sleep sack will replace loose blankets in the crib and will keep your little one cozy, warm and secure throughout the night.