[Material Description] Polyester [Accessory structure] 3 in 1 backpack set, 17 inch backpack + lunch bag + pen bag [Product performance] Preferred material: Our product set is made of polyester material, wear resistance, shrinkage resistance and tensile properties. Rugged: This backpack has reinforced anti-wrinkle details on the bottom to ensure that the bottom of the backpack is firm, reinforced to protect the backpack, and adjustable shoulder strap reinforcement. Keep your back comfortable. Lightweight and portable: Small in appearance but large in capacity, this lunch bag is perfect for your lunch box, snacks, fruit, and even protein shake bottles. Meet your daily needs. Easy to carry, pick up and go. Versatility: This pen case can hold pencils, pens, erasers, watercolor pens and other items. Strong functionality, wide range of application. It is suitable for children's daily school and leisure day trips, or office workers who have already worked, and it is a very good combination. [Washing instructions] It is recommended to wipe and clean with a wet cloth regularly. [Special Note] This size data is measured under the tile, due to different measurement methods, error within 1cm is a normal phenomenon.