Claim: Lightning rod are called finials.

A lightning rod -LRB- US , AUS -RRB- or lightning conductor -LRB- UK -RRB- is a metal rod mounted on a structure and intended to protect the structure from a lightning strike . If lightning hits the structure , it will preferentially strike the rod and be conducted to ground through a wire , instead of passing through the structure , where it could start a fire or cause electrocution . Lightning rods are also called finials , air terminals or strike termination devices .   In a lightning protection system , a lightning rod is a single component of the system . The lightning rod requires a connection to earth to perform its protective function . Lightning rods come in many different forms , including hollow , solid , pointed , rounded , flat strips or even bristle brush-like . The main attribute common to all lightning rods is that they are all made of conductive materials , such as copper and aluminum . Copper and its alloys are the most common materials used in lightning protection .