-SUPER SOFT LIGHTWEIGHT 100% ORGANIC COTTON – The Wearable Blankets are made of super soft, lightweight, and breathable premium organic cotton to keep your baby warm, cozy, and sleeping peacefully. The lightweight and breathable cotton interlock fabric minimize the risk of overheating and keep your baby comfortable -SAFER DETAILED DESIGN- 1. 100% SAFE. Having the zipper protector at the top! This helps from the zipper tail digging into the baby and causing any discomfort. 2. SLEEVELESS. Faster and easier to put on or off. Baby can still move arms freely. 3. INVERTED ZIPPER. Zip up from the bottom - Making it easy to change diapers in the middle of the night -GENEROUSLY SIZED AND ROOMY – Our sleep bags are generously sized to fit over sleepwear and carefully designed so the baby's leg can move freely to ensure proper hip development. Medium size sleep sacks fit babies from 6-12 months, 16-24 lbs, 26-30" -COOL & COMFY, YEAR ROUND - We leverage the soothing softness of hand-selected 100% pure cotton which is a fancy way of saying this is the ideal wearable blanket for babies' porous, sensitive skin. Wear alone in the hotter months or pair with warmer jammies to stay toasty and content during drafty winter days