1. ### Features 1. Brand new and high quality. 2. The backpack trolley is made of high - quality aluminum alloy, which is strong and durable. 3. It has three height adjustment levels of 43/66/90 cm and can be stretched with one key. This trolley is very suitable for students' schoolbags. 4. This foldable schoolbag trolley is specially designed for students' schoolbags. The six wheels can roll smoothly on the stairs, which is labor - saving and convenient. 5. Whether on flat ground or stairs, it can effectively reduce the burden on children's shoulders and spine. 6. As an ideal gift for children, this stylish backpack trolley is very suitable for travel, school and hiking. 2. ### Specifications 1. Material: Aluminum alloy. 2. Dimensions: Approximately 43x27x19 cm/16.93x10.63x7.48 inches (foldable). 3. Types: Six - wheel crystal wheel dark blue model / Six - wheel crystal wheel rose red model / Six - wheel blue rubber wheel model / Six - wheel three - color wheel rose red model / Six - wheel crystal wheel blue model. 3. ### Precautions 1. Due to manual measurement, a 1 - 2 cm error is allowed. 2. Due to differences in different monitors, the pictures may not reflect the actual color of the item. 4. ### Package Contents 1 backpack trolley.