Features: 1.TROLLEY BAR DESIGN: The unique design of the trolley bar reduces resistance and vibration when pulling the bag up the stairs, and reduces the hand discomfort brought to the children by the overweight pulling force. 2.METAL ROD: The rod is strictly selected aluminum alloy material, premium materials, stable bottom, sturdy and durable. 3.WEAR RESISTANT: PVC wheels, nonslip and wear resistant, shock absorbing effect is good, lightweight wear resistant and durable, firm grip. 4.WATERPROOF FABRIC: The schoolbag is made of high density waterproof fabric, waterproof principle, rain falls on the schoolbag naturally slides off. 5.LARGE CAPACITY: The trolley backpack offers ample storage space to accommodate plenty of books, stationery, and kids belongings, meeting the daily learning and living needs of students.specification:Item Type: Rolling Backpack Material: Nylon, Polyester, Aluminum Alloy RodPackageList:1 x Backpack1 x Trolley Bar