The Perfect Aircraft Diorama Addition This kit is perfectly suited to displaying alongside aircraft models, as it features a WWII German Kettenkraftrad with a power supply unit used with Luftwaffe airplanes. The set also includes two engineer figures that may be posed charging an aircraft battery. Many photos from wartime Germany show the power supply unit installed on a two-wheeled cart that could be easily towed. The Kettenkraftrad was a unique half-track motorcycle that was used for a variety of purposes, including towing and servicing aircraft.