Sleep as Babies’ Like - Over 90% of babies sleep with their ARMS UP around their head when placed on their back to sleep. This is simply a newborn baby’s natural and preferred way to sleep. Knirose swaddle with scientific Arms Up design allows baby to sleep with their arms in their preferred ARMS UP position and gives enough movement, all while calming down the Moro (startle) reflex. | Enjoy Sleep - We know that you will feel very tired, because you hardly have a good night's sleep, because the newborn baby is easily awakened, or crying at night, or needs to be hugged to sleep, etc. This snug fit swaddle creates a familiar safe and secure feeling just like in mommy's womb, and it also mimics your baby feels when held by you. This ensure your baby is comfortable throughout their sleep cycles in the night and enjoy sleep. | No Disturb by Diaper Changes - Are you worried that the change the diaper will wake the baby up? Knirose swaddle sleep sack as an awesome dual 2 way zipper from side to the bottom makes it is an easy job for middle of the night diaper changes and hardly disturb your little sweetie. The zippers are well kept hidden for babies not to get a rush or something. | Multipurpose Design - This swaddle grows with your newborn and infant until next stage. Plus, allows your baby to sleep with arms in/out/free position. The ability to swaddle with arms out or in makes it perfect for transitioning when the time comes. And it allows babies to move arms and if the babies are to roll onto their stomach they would be able to use their arms to lift their head off of the crib mattress if needed. And it has lots of room for kicking legs. | Premium Materials - We always know the concerns of being a parent that you hope fabric is soft and comfy. The snug fit from our 4-way stretch fabric of 95% Cotton and 5% Elastane and has a TOG rating of 1.0 which makes it perfect for year-round comfort. The fabric is elastic like mother's womb, so familiar. These swaddles are baby registry must haves for new parents.