Via ferrata are mountain routes that have wire cables running along them that you clip into for protection.
Route features include metal rungs, footplates, ladders and bridges to help you ascend, descend and traverse as you go. An essential piece of kit for anyone wanting to tackle via ferrata is a purpose built set which includes a shock-absorbing lanyard.
Petzl and Edelrid both produce excellent via ferrata sets that include shock-absorbing lanyards with easy to use carabiners for smooth clipping into the cables.