High Material and free guarantee: The vertical laptop dock is made from sturdy heavy due aluminum alloy to prevents your laptop from falling down.Please contact us if you have any question. Protective and Stable: Anodized aluminum is scratch-resistant and durable. Non-toxic silicon mate protects your MacBook from being scratched and secures it in stable position. Wide Compatibility: 4 in 1 design makes it convenient to place your devices. Compatible for iPad/iPhone, Apple MacBook Pro/Air, Microsoft Surface, Gaming Laptops, Notebooks, Dell Samsung Lenovo Acer Sony Asus XPS and HP ENVY Series or even books. Adjustable size: Adjustable for laptop width with thickness from 0.63in /16mm to 2.36in / 60mm, you could adjust the screw to tighten down to correct size. Dual slot design:Cradle up two laptops and phone ipad vertically at the same time. The laptop holder is great for space saving and building up a neat and organized space for desk.