Merlin's magic Sleepsuit Size Large - 6-9 months or 18-21 lbs Cotton version New with tag Smoke free and pet free home. The Magic Sleepsuit is apatented swaddle transition product created by a pediatric physical therapist and mother of four. It is designed to help your little one when breaking out of the swaddle but still seeking the safe and comfortable feeling that the swaddle provides. The Magic Sleepsuit provides that cozy feeling while allowing your baby the freedom of movement they need as they develop.