Large Capacity :Over 20L volume is enough for family use,the expand size of bag:40*2332*25cm, great for packing large amounts of food, fruit, drinks and will keep them fresh all the time.Maintain a stable temperature environment for food. High Quality :The picnic bag is made of environmentally friendly material, aluminum frame and polyester cloth surface make this it really sturdy, waterproof, lightweight, and its wear resistance and wrinkle resistance is also very good.Since its waterproof and oilproof,it is so easy to clean. Collapsible Design :The folding size of bag:40*6*25 cm,easy and Convenient to store in the cargo space of cars or limited space. Multi-Purpose :It is great for store plenty food and keep them cool, fresh. Keep Warm: pizza and other cooked food (about 4 hours). Keep cool: can store iced fruit and drinks, breast milk, seafood, etc.