SIZE SMALL/MEDIUM: The SwaddleMe® Night Sack Sleeper in this size fits babies 0-3 months, 7-14 pounds, up to 26 inches long. ARMS OUT: This newborn swaddle sleep sack can be worn from birth. It's designed for babies who resist swaddling and prefer their arms free so they can self-soothe. SAFE AND SECURE: A wearable blanket eliminates the need for loose blankets in the crib. It has an extra-wide hip area so baby can move, and a two-way zipper to make diaper changes a breeze. SOFT AND COMFORTABLE: This soft swaddle blanket is made out of durable natural fiber (100% cotton) and is machine washable. STAGE 3: The SwaddleMe Night Sack Sleeper is part of Stage 3 in the SwaddleMe Stages of Sleep. These arms-out swaddle options keep babies and toddlers warm and safe. 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. Baby 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 leaves plenty of room to move, and a two-way zipper makes it possible to change a diaper without waking baby. At SwaddleMe, we know that being well-slept leads to a happier life for babies and parents. Expanded assortment available online. This item not carried in store.