33" ribbed back wheels Accurate markings Incredible detail True to prototype Non-magnetic Metal wheels Highly Flexable sprung trucks Metal SideFrames & Bolsters Fully Sprung Smooth tracking Free rolling Contoured Insulated Axes RP-25 Free rolling wheels.The Bettendorf T-Section truck was introduced in the 1920's with a one piece cast sideframe. It had a life similar to the Andrews truck.