100% Cotton Comfort - This baby sleep sack made with 100% cotton, super soft and breathable for comfort. The sleeveless design helps regulate baby's temperature, reducing overheating risk and ensuring warmth and cozy. | Safety & Carefully Sized - Yoofoss baby sleep sack are CPSC-certified for your baby's safety and comfort. The neckline has been carefully sized and numerous experiments ensure a secure and snug fit, preventing the baby from slipping into the sleeping sack. And the loose around the legs to allow for natural hip development. | Smooth Double Zipper - Our wearable blanket baby feature a 2-way zipper, so you can unzip from the bottom to to change diapers, disturb baby even less during the night. Then you can enjoy a sweet night with little one ! Zipper protectors on the top will protect baby's jaw from scratches. | Lightweight 0.5 Tog ：The baby sleep sack 0.5 Tog is suitable for moderate temperatures from 75 to 80°F as an ideal option for spring, summer, autumn or taking a nap in air-conditioned rooms.We insist on quality control of baby wearable blanket, it can be withstand millions of washes and achieve a shrinkage rate of less than 2% after machine washing and dry on low heat (<30°C/86°F). | Our Original Design 3 Pack baby sleep sack is perfect as baby shower gift or baby registry and suitable for both baby girls and boys.There are 4 sizes available for your choices: S(0-6 Months), M (6-12 Months), L(12-18 Months), XL(18-24 Months).Please refer to our size chart carefully before you order our baby wearable blanket.