The exterior of the lunch bag is constructed out of water-resistant Oxford fabric for durability and water proofing and easy cleaning. the interior lining is made from high quality aluminum foil and 5mm EPE foam to offer great thermal resistance. The Bag comes with a zipper closure design for easy opening. The high quality aluminum foil lining offers great thermal resistance which keeps the food fresh and warm/cold. It is ideal for storing foods to bring to school, workplace, picnic, beach and BBQ. It is also great for maintaining cold drinks or ice pack temperatures at the gym or in the car.