What is "kugelpanzer"

The Kugelpanzer literally translates as "Ball Tank" and is perhaps one of the rarest and most strange armored fighting vehicles ever built. Only one lone example of this Reconnaissance Rollzeug (Rolling Vehicle) was captured by the Russians and it survives today as part of the Kubinka Museum's collection of German armored vehicles. The Kugelpanzer is simply listed as Item #37 and has been painted over gloss white. From fragmentary information sources, it is believed that the drive has been removed from the vehicle and no metal samples have been allowed to be taken from it. The history of the vehicle is unknown, as no documents were found with it and the vehicle had no clear markings.