The Halo SleepSack 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"s 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"s time to stop swaddling. Used in hospitals nationwide, the Halo SleepSack Swaddle is the number 1 choice of hospitals, recommended by safety organizations and is approved as Hip Healthy by the International Hip Dysplasia Institute. The HALO SleepSack Wearable Blanket Cable Knit features: * 100% cotton. Size small fits 10-18 lbs, size medium fits 16-24 lbs. * Use over regular sleepwear to take the place of loose blankets * Sleeveless design reduces the risk of overheating * Generous sack design allows room for kicking, but cannot be kicked off so baby stays warm all night * Used by hundreds of hospital nurseries nationwide as their product of choice for teaching parents safe sleep practices HALO supports non-profit organizations like First Candle SIDS Alliance and The Canadian Foundation for the Study of Infant Deaths.