Applicable school age: elementary school Material: Oxford cloth Bag size: medium Capacity: 20-35L The internal structure of the bag: zipper pocket, mobile phone pocket, ID pocket, sandwich zipper pocket, computer pocket, camera pocket Opening method: zipper buckle Function: breathable, waterproof, wear-resistant, anti-theft, anti-vibration, lightening Strap root number: double root Style: Japanese style Lining texture: polyester Hardness: medium to hard