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. Warmth 1.0 Tog: With two layers cotton fabric, the 1.0 TOG baby sleep sack is perfect for all-year-around, keeps baby cozy and comfortable in A/C room or restaurant, when travelling or napping.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 (