Made from 100% organic muslin cotton, our Sleep Bags are the perfect summer weight for a peaceful night's sleep. The Sleep Bag Thermal Overall Grade 1 TOG is lightweight and perfect for warmer months. With 2 layers of muslin, it's both breathable and incredibly soft. It also unzips side to bottom with a zipper for easy diaper changes. Designed for little one's comfort and your piece of mind, we added under-arm snaps in our 0-9 month size to ensure a perfect fit for your growing baby.