SIZE DESCRIPTION - Our infant sleep sack is specially designed for newborn 0-6month size, recommended max height is 26 inches(66cm), recommeded max weight is 17.5 lbs(8kg), available for all seasons. Please feel free to contact us with any question. INCOMPARABLE DETAILS - Adequate zipper protectors on the top can protect baby's jaw from being scratched. The two-way zipper system can open from the bottom for easy diaper changes. Cuff and neckline are sized for a safer fit. Fasteners and velcro on the swaddle provide adjustability for a perfect fit for baby's size and needs. Easy-open bottom design meets the need of leg movement as baby grows up. SELECTED LONG STAPLE COTTON - The baby swaddles 0-3 months is made of long staple cotton from 100% natural cotton which is 3X softer than normal cotton and keep baby warmer at room temperature 18? to 26?. The inner surface is slightly fleeced, more skin friendly and comfortable to baby's sensitive skin. 3-WAY SLEEPSACK SWADDLE - Our newborn sleeping bag can be used in different ways for different levels of growth babies. It allows Arms-In to prevent startle reflex, Hands-to-Face for self-soothing, and 1 Or 2 Arms Out for easy transition from swaddling to sleepsack. Swaddle blanket wrap arms for the newborn(0-3 months), one or both arms out for 3-6 months babies(when baby showing the signal of rolling). DESIGNED FOR A GOOD SLEEP - Duomiaomiao baby swaddle blanket replaces loose blankets in the crib for a safer environment. Our baby swaddles for 0-6 months designs a detachable wing to help newborns promote self-soothing and prevent waking up suddenly during the startle reflex, giving baby a longer and sweet sleep. You can enjoy more sleep when your baby learns to comfort himself.