*for 13-18.5lb* The Zen One swaddle blanket and sleep sack perfectly adapts to your baby's needs - scientifically designed to help babies self-soothe and get sounder sleep as their sleep styles change, from birth through rolling, the Zen One functions as both a snug swaddle and a wearable blanket. Made of snug but stretchy fabric and loaded with versatile features, the Zen One has 3 gently weighted Cuddle Pads™ that, unlike other baby swaddles, provide comforting pressure only where babies are naturally used to being held, mimicking your embrace and encourage sleep. This light pressure also prevents wakeups from your baby's startle reflex, and helps your baby sleep for deeper, longer stretches. The Zen One has a snug inner band to hold arms down and prevent startles while your baby sleeps, quick-dry mesh sleeves to help thumb suckers self-soothe, and removable sleeves that allow for arms-out swaddling when your baby rolls and you need to stop swaddling. Whichever way you use the Zen One, a 2-way zipper makes diaper changes a breeze compared to traditional swaddle blankets. A favorite of over 2 million families, the Zen One is approved by pediatric pulmonologists, exceeds all safety benchmarks. and is backed by a recent university-led weight safety study, so you can sleep soundly knowing your little one is in safe hands in their dream swaddle.