The BreathableBaby® BreathableSack™ Wearable Blanket is designed to be the most comfortable wearable blanket on the market. It replaces loose blankets in the crib that can cause suffocation or rebreathing carbon dioxide – both leading causes of SIDS. The BreathableSack™ also helps prevent overheating. Overheating is also a leading risk factor for SIDS. When babies get hot and perspire, the moisture wicking liner and breathable plush outer fabric helps keep babies dryer and more comfortable. There’s a cover for the zipper pull so that when your baby is wearing it, the zipper pull won’t touch their skin. The zipper also goes both up and down to make diaper changes easier.