Excellent quality The radiator backpack is made of strong polyester fabric and high quality oxford fabric, with waterproof PVC coating on the back, non-fraying seams, strong and durable zipper. Has excellent heat resistance. Premium food-grade inner reservoir features a waterproof and stain-resistant inner cooler that's easy to clean and keeps your food dry in the cooler bag Thermal protection and cooling The picnic backpack is made of EVA insulation and PVC coating. The inner liner is food grade PEVA and is filled with 6mm EPE foam which can keep the backpack hot and cold for several hours and keep food fresh, depending on the item inside, and the bag is waterproof Upgraded Easy to clean inside and out. Durable cooler bag suitable for beach picnic, family vacation, camping, walking, hiking or similar activities Comfortable to carry This backpack for men and women has a large capacity and light weight. Adjustable shoulder straps and ergonomic design, mesh padded shoulder straps and back for comfort and good ventilation when carrying many items