Kadee HGC 2-Piece Trucks for HOn3 narrow gauge cars are made of a high-gravity metal-plastic hybrid compound (HGC) that weighs almost as much as metal. The two-piece design allows full equalization without need for springs. Truck sets include center bushing adapters for attaching the trucks to various makes of cars. The trucks require a flat mounting surface and some models may require trimming and filing of the car's bolster to make a flat surface. The bushings are designed for the original screws or where appropriate 0-48 self-tapping, 0-80 machine screws, or 1mm to 1.25mm metric equivalent. HGC 2-Piece Trucks include 26" ribbed-back RP-25 contour metal wheels, insulated axles and three assorted metal mounting bushings.