The hooks are extremely sturdy and can support bikes up to a maximum weight of 30kg. The hooks are made from strong metal but are covered in soft TPE plastic ensuring that your bike will not be scratched or damaged whilst hanging from the wall. The hinged design allows the hook to be folded flat against the wall when it is not in use, simply fold the hook down as and when required. They are extremely easy to install, ensure appropriate fixing screws and plugs are used to fit the hanger. (Not Included) The hook diameter is 8.6mm and the thickness of the plate is 2.5mm.