Introducing the HapBoby Backpack Trolley - Next Generation Silent Large Wheels Backpack Trolley.Easily convert your ordinary backpack into a convenient wheeled luggage cart with the backpack trolley. Specifically designed to securely hold a regular backpack in place, effortlessly transforming it into a trolley bag. Ideal for teenagers, adults, travelers, and those on the go.Specifications: Available in 2 styles.Base without border: 11.5x7.1in (29x18cm).Base with border: 12.4x7.87in (31.5*20cm).Please carefully review the size specifications and measurement instructions to ensure the purchase of the correct product.Materials: Aluminum alloy, PP, foam rubber.Features:This silent large-wheel backpack trolley is designed to easily convert your regular backpack into a convenient wheeled luggage carrier..Elevated base design - Trolley base sits 4.7in/11cm above the ground, preventing your backpack from dragging.Easy installation - No screws required for assembly.Large foam rubber wheels enable smooth navigation on various terrains, including stair-climbing. Minimal noise on flat surfaces ensures effortless transportation, whether on even ground or stairs, reducing the strain on shoulders and spine.The backpack trolley features adjustable height settings - 24in/35.4in/40.9in, catering to individuals of different heights, suitable for teenagers and adults.The foldable trolley base is constructed from sturdy eco-friendly PP, equipped with an extendable aluminum alloy handle, noiseless large wheels made of foam rubber, with a maximum load capacity of 77 lbs.Versatile applications - Ideal for travel, and daily use.Package Contents:1 x Wheeled Backpack Trolley2 x Buckle Straps