Cotton+polyester Imported Soft Cotton Outer: The baby sleep sack is crafted from 100% cotton fabric and filled with soft polyester, offering an incredibly gentle and breathable experience for baby's delicate skin. The sleeveless desisn and the generous bottom space of our toddler sleeping sack allows for arms and legs‘ movement. Warmhearted Design: Looxii baby sleep sacks are CPSC-certified, ensuring your baby's safety and comfort. The neckline of our 2.5 tog sleep sack is carefully designed and tested to provide a secure and comfortable fit, preventing your little one from slipping inside. The sleeveless design prevents the risk of overheating. Durable Quilted Design: Our sleep sack is rated 2.5 tog. The unique double quilted pattern evenly distributes the filling, preventing lumps and shifting. It's more durable than regular baby wearable blankets and can withstand numerous washes with minimal shrinkage. We've refined our sleep sack to achieve a shrinkage rate of less than 2% after machine washing and drying on low heat. Smooth Two-Way Zipper: Our baby wearable blanket features double zippers, allowing you to easily change diapers by unzipping the toddler sleep sack from the bottom without waking up your baby. The zipper protectors on top prevent scratches on your baby's jaw. Warming Tips: For colder temperatures, you can layer the winter sleep sack with warmer sleepwear. It's suitable for room temperatures ranging from 61°F to 68°F. Available in four sizes: S (0-6 Months/10-18 lbs), M (6-12 Months/16-24 lbs), L (12-18 Months/22-28 lbs), and XL (18-24 Months/26-34 lbs). Please carefully refer to our size chart before ordering our baby wearable blanket. This baby sleeping bag is designed to keep your little one warm and cozy during the cold winter months. Made from soft and breathable materials. The sleeping bag features doublezippers to change diaper easily at night.