Happiest Baby's Sleepea is the best swaddle...ever! No more frustrating baby origami! Dr. Harvey Karp, the pediatrician who started the Swaddling Revolution, designed every detail of Sleepea with baby safety-and parent sanity-in mind. Wrapping gives the constant embrace babies love in the womb. It quickly boosts baby's sleep by preventing startles and wild-hand nose-whacks. Safer - Snug swaddling reduces baby's ability to roll to a risky position. Can't unravel, so no loose blankets around the face. Hip healthy - Extra room for healthy growing hips. Prevents overheating - Open-weave mesh Easy - Super- simple... literally a 5-second swaddle! Ergonomic- Not too loose, not too tight... perfect wrap every time 2-Way zipper - Zips from the top or bottom, for fast diaper changes Smart inner band - Keeps Houdini babies from breaking out! Special 'quiet' Velcro- Won't disturb baby when you open it Arm holes- Medium and large have optional arm holes to make it easy to wean the swaddle 100% organic cotton - So, it's good for your baby... and the planet! Now, anyone can become a master swaddler...in just a day! Recommended weight ranges by size are as follows: Small: 5-12 lbs Medium: 12-18 lbs Large: 18-26 lbs