Ships from Hong Kong. Your baby's favorite pajamas, this muslin wearable blanket does away with loose blankets in the crib-creating a safe sleep for baby and peaceful night for you. Easy to put on or take off. it is the best baby sleep sack. Cotton Muslin Sleepsack Wearable Blanket. Made with two layers of lightweight and ultra-soft cotton muslin, it is exceptionally breathable for optimal airflow, reducing your baby's risk of overheating and ensuring comfortable sleep. Unzips from the bottom for easy diaper changes.