Lunch Bags for Women Men Reusable Insulated Lunch Box Portable Thermal Cooler Bag Waterproof Bento Box Bag Lunch Box Tote Bag. The lunch bag liner is made of aluminum foil material, BPA free, and has good insulation and cooling effects, which can keep food warm/cool for up to 5 hours. The surface of the lunch bag is made of Oxford fabric, which has good waterproof effect. Easy to clean and can be hung for storage. Cannot be used for machine washing or dishwashing.