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. The Halo SleepSack Swaddle is the #1 choice of hospitals, recommended by safety organizations and is approved as "Hip Healthy" by the International Hip Dysplasia Institute. A portion of every purchase goes to 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.