About this item Zipper closure 【Durable Material】- 50L. 600D polyester fabric. YKK Zipper and YKK Buckle. Rain cover included. 【QUICKLY ACCESS】- The internal frame backpack has large zipped access at front that can quickly access to the main compartment,opend as a luggage. Comfort & Durable: Made of breathable nylon material, lightweight and soft that suits adults, teenagers, and kids while camping or on an outdoor adventure. Humanized Design: Two-way zipper design is convenient for ventilation while locking in heat. The bottom is also a zipper design means that your feet can expand for ventilation. Multipurpose: After the sleeping bag is unfolded, it can be used as a quilt or a sleeping pad. You can also splice two sleeping bags up and down after they are fully developed, making it a double sleeping bag that is a perfect choice for couples or families.