100% Cotton Soft and Cozy - This baby sleep sack made with 100% Organic cotton, super-soft and breathable for comfort. Sleeveless design helps regulate baby's temperature, reducing overheating risk and ensuring warmth and cozy. Safety Sleep - 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. 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, keeping your baby snug and warm. Smooth 2-way Zipper - Our Baby wearable blanket feature a double zipper, so you can unzip from the bottom 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. Please refer to our size chart carefully before you order our baby wearable blanket.There are 4 sizes available for your choices: S(0-6 Months), M (6-12 Months), L(12-18 Months), XL(18-24 Months).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 (