This lightning rod took it’s name because of Benjamin Franklin’s experiment. It is used in narrow but high buildings such as light houses, towers and chimneys. Princeply you have to mount a passive lightning arrestor to top of the building which you want to protect and you have to earth it with a conductor. The main thing you have to know about franklin rod is their protection area is due to their height. Franklin rods protection area is in a conical shape. This conical protection area is named as Franklin Cone.