The Swaddle UP is the only zip-up swaddle available that allows your baby to sleep in the arms UP position. The Swaddle UP requires no complicated wrapping, so everyone can swaddle right every time. Materials: 93% Cotton, 7% Elastane Snug fit makes your baby feel secure & helps to calm their natural startle reflex Eliminates excess loose fabric in the crib Wings prevent face-scratching May reduce the risk of your baby accidentally rolling onto their tummy Genius two-way zipper for easy diaper changes Hip-healthy design allows hips and legs to flex naturally