HO Scale Pennsylvania 2D-F8 50-Ton Self-Centering Trucks, featuring 33" Ribbed Back Wheels, are meticulously crafted in metal and fully sprung. They can be mounted with or without the Kadee Self-Centering bushing, using a #2 or 2-56 screw on a flat surface, or secured directly onto a 0.140" or smaller truck post. Introduced in the 1930s, these trucks served loyally for over five decades. Our model represents the 1930s style with a cast steel bolster, unlike the earlier riveted bolster version. These trucks are renowned for their durability and accuracy, capturing the essence of the original Pennsylvania Railroad Class 2D-F8 freight trucks.