An upper-limb amputation provides a very different challenge, as the function of the human hand is much harder to replicate than the function of the foot. Modern technology can provide a high level of function with the use of electronic sensors and robotic hands. Often a person may simply wish to have a prosthetic arm that is cosmetically attractive and not as functional. There are also a wide variety of functional devices that can be used in place of a hand – such as a hook, tool holder, knife or steering wheel attachment. While they may look unusual, many people find the added function invaluable when performing certain tasks.