This is a locomotive body of the HF twin CC. Illing Lok B is the lower one of the two vehicles. The body is hollowed in areas of the boiler, the water boxes,the domes and the firebox and the ash box. See product pictures, there are shown the dimensions of a chassis for this vehicle. Note Mark Clark from www.locosnstuff.com plans to build such drives for 12mm to 16,5 mm..