Swaddling has been around for ages as it helps to prevent the startle reflex. But forcing the baby’s arms to their sides or over their chest prevents two natural behaviors that frustrate the baby and they fight to get their hands free. | First - Over 90% of babies sleep with their ARMS UP around their head when placed on their back to sleep. This is simply a baby’s natural and preferred way to sleep, just like in the womb! | Second - All babies are born with the need to SELF-SOOTHE by touching their face and sucking on their hands as they did in the womb. This medically proven behavior is how a baby calms and falls asleep on their own. Traditional swaddling prevents this. | The patented wings on the Swaddle UP allow the baby to both sleep with their arms in their preferred ARMS UP position and gives enough movement so they can SELF-SOOTHE, all while calming down the startle reflex. | The snug fit from our 4-way stretch fabric of 93% Cotton and 7% Elastane creates a familiar and secure feeling just like in the womb to calm the Moro (startle) reflex. Does not contain flame retardants or any harmful chemicals. | The dual zipper makes diaper changing a breeze and eliminates the need to remove the swaddle and having to completely re-swaddle the baby. The patented design eliminates any risk of loose fabric and the zipper replaces noisy Velcro or bothersome snaps. | The unique wing design eliminates face scratching from baby’s sharp finger nails. All seams are sewn on the outside and the zipper is protected so there is nothing rough against baby’s skin. | Medium size designed to fit babies from 13 lbs. up to 19 lbs., approximately 3-6 months. The Swaddle UP Original is 1.0 TOG. | Once baby shows signs of rolling over, it’s time to transition to arms free sleep. The Stage 2 - Swaddle UP 50/50 Transition Bag will ease with this transition from being swaddled.