Nothing to attach or assemble prevents your notebook from overheating; the more air under the notebook, the greater the heat dissipation protects furniture from heat damage; protects notebooks from liquids spilled on work surface ideal for presentations: pivots your notebook 360 degrees so others can see the screen can be used anywhere: at work, home or school adjust keyboard to a comfortable height with the stackable risers works with all notebooks rubber feet keep notebook from moving on airline trays and other slippery surfaces weighs 630g lifetime warranty optional: usb2.0 hub 4 port is optional. weights of hub is 120g.