The Halo SleepSack Swaddle replaces loose blankets in the crib that can cover your baby's face and interfere with breathing. In addition to helping your baby sleep safer, it helps him sleep better, too. Its adjustable swaddle wrap immobilizes your baby's arms to prevent the "Moro" or startle reflex. And, it is the only 2-in-1 adjustable swaddle that allows for swaddling arms in or arms out for baby's comfort and to ensure an easy and gentle transition to the SleepSack wearable blanket when it is time to stop swaddling. Used in hospital nurseries nationwide, the Halo SleepSack Swaddle is the #1 choice of hospital nurseries, recommended by safety organizations and is recognized as "Hip Healthy" by the International Hip Dysplasia Institute. HALO supports non-profit organizations like First Candle/SIDS Alliance and The Canadian Foundation for the Study of Infant Deaths. Use over regular sleepwear to take the place of loose blankets. Discontinue swaddling when the baby shows signs of rolling over or breaking out of the swaddle wrap. 100% cotton interlock. Size newborn fits 6-12 lbs, size small fits 13-18 lbs.Features2 in 1 adjustable swaddle that allows for swaddling arms in or arms out for baby's comfort; 100% cotton interlock; Size preemie fits birth 5 pounds, size newborn fits 6 12 pounds, size small fits 13 18 poundsUse over regular sleepwear to take the place of loose blankets; Discontinue swaddling when baby shows signs of rolling over; Unzips from the bottom allowing baby to stay swaddled for easy diaper changesSleeveless design reduces the risk of overheating; Generous sack design allows room for kicking, but can't be kicked off so baby stays warm all nightUsed by hundreds of hospital nurseries as their product of choice for teaching parents safe sleep practices; Approved as Hip Healthy by the International Hip Dysplasia InstituteEmbroidery reminds caregivers to place baby on his or her back