This baby swaddle sleep sack with big bow hat is made of premium natural cotton and stretchy polyester that is lightweight and breathable. The smooth and stretchy fabric has excellent breathability which can prevent overheating and ensure that babies sleep peacefully providing them with a more comfortable sleeping experience. Our baby blankets are designed with adjustable wings which can adjust the tightness of the swaddle according to the needs and let your baby sleep comfortably and our baby sleep sack is a wearable wrapping blanket that is easy to put on and take off making it convenient to change diapers while the baby is sleeping without opening the bag. The baby blanket sleep sack can wrap babies in swaddling in just four simple steps which is perfect for new parents looking for newborn swaddles to use. Our swaddles for newborns are particularly durable and long lasting combining functionality and comfort and the baby blanket provides a comfortable and secure environment that simulates the mother womb helping to reduce the startle reflex and promote longer more stable sleep.