Waterproof,Foldable and retractable Our food delivery bags have such great advantages. Warm and cold insulation. 500D PVC outside, 5mm insulation foam inside, aluminum foil lining, PVC zipper, and food grade hollow plate. The aluminum foil inner lining is ideal for adding a layer of insulation to both hot and cold items so that you can keep your food fresh for delivery, picnics, hiking, kayaking, camping, the beach and other outdoor activities!