Designed as the perfect swaddle for newborns our arms up swaddle allows your baby to sleep in their natural arms up position making it easier for them to self soothe by bringing hands to their mouth. The snug fit around the chest mimics your gentle hold calming the startle reflex for deeper more restful sleep night after night. The two way zipper lets you unzip from the bottom for quick diaper changes while keeping your baby warm and cozy and this baby swaddle sleep sack is designed for real life convenience even at 3 AM. This transitional sleep sack has a two in one design that allows arms up or hands out swaddling so you do not need to buy separate newborn swaddle and transition sack and one piece meets your baby sleep needs as they grow. Made from premium muslin fabric this baby sleep sack is soft lightweight and gets even softer with every wash and our breathable cotton helps regulate temperature and reduces the risk of overheating.