Wee Urban"s Cozy Basics Sleep Bag is a wearable blanket available in 3 sizes, 0-6, 6-18, and our best-selling 18-36 months. Our two way zipper opens at the bottom and on the side making diaper changes or dressing a sleeping baby effortless. Cozy Basics Sleep Bag features a "hide and lock" zipper to prevent toddlers from unzipping the bag. Simply insert the zipper slider inside the sack. By adding or removing layers of under garments, The Cozy Basics Sleep Bags are a year-round essential for your child rather than just a seasonal investment. They are the perfect alternative to loose blankets in the bed and a perfect way to help baby maintain a safe and long restful sleep. Remember when baby sleeps well so do you.