The Kettenkrad is one of the most unique vehicles developed during WWII. The "tracked motorcycle" concept was in response to a request for a fast, tracked vehicle capable of moving small loads in mountainous terrain.
One of the variants of the Kettenkrad is Sd.Kfz. 2/2 "kleines Kettenkrad fur sch. Feldfernkabel" that has two big field communication wire spools mounted on a frame behind the driver seat.