The SwaddleMe Night Sack Sleeper is a sack-style wearable blanket that keeps baby safe and cozy while eliminating the need for loose blankets in the crib. Sleep sacks are designed to be layered over pajamas, leaving baby's arms free. The Night Sack Sleeper is perfect for little ones who are transitioning out of wrap and compression swaddles, or who don't like to be swaddled tightly. The hip-healthy design allows plenty of room to move around. And a two-way zipper makes nighttime diaper changes easy. At SwaddleMe, we know that being well-slept leads to a happier life for babies and parents.