The Cocoon Swaddle bag is made from natural fibres GOTS certified organic cotton and bamboo with a touch of elastane. This means it's firm enough to restrict startle reflex whilst still allowing stretch and movement for healthy growth. The stretch also allows for full chest expansion when breathing, added comfort, and for a baby to move its hands into a self-settling position inside the swaddle. The soft, breathable organic cotton and bamboo is certified non-toxic, dyed with water based dyes, and gentle on newborn skin, and skin prone to eczema breakouts. A zip enclosure also protects your child's delicate skin, and the handy arm poppers transition the Cocoon from an arms-in swaddle to arms-out sleeping bag when baby is showing signs of rolling. The bell shaped design is approved by the International Hip Dysplasia Institute as being hip-healthy, and promotes proper joint development in the hips and shoulders joints. Finally, the two-way zipper makes for quick and easy nappy changes during sleep with minimal disruptions.