The ASF(R) 100-ton Roller Bearing Truck is from the modern diesel era. It has standard 36-inch wheels and a longer wheelbase than the 50- or 70-ton roller bearing trucks. This model is a faithful reproduction of the American Steel Foundries(R) Ride Control(R) truck. This truck is currently in use under a variety of rolling stock in North America. Self-centering action trucks self align themselves parallel with the car for easier placement on track. Mounts with a #2 or 2-56 screw. 2-piece fully equalized trucks. 1pair.