Vulcan Double Truss Fully Sprung Self-Centering Metal Trucks Code 110 (.110") 33�Õ Ribbed-Back RP-25 Wheels 1 Pair by Kadee Quality products / HO Scale Metal fully sprung equalized trucks mount with a #2 or 2-56 screw, sold separately. The Vulcan truck was introduced in the 1920s as another replacement for the arch bar truck. The Vulcan design incorporated a pin that held the journal box in place. Removal of the pin allowed the journal box to be quickly replaced. This truck lasted to the end of the steam era on mainline railroads and somewhat longer on logging railroads. Truck Features: * Self Centering Action - Trucks self align themselves parallel with the car for easier placement on track * Code 110 (.110) 33} ribbed back wheels * Accurate markings * Incredible detail true to prototype * Non-magnetic metal wheels * Highly flexible sprung trucks * Metal side frames and fully sprung bolster * Smooth tracking free rolling contoured insulated axles * RP-25 free rolling wheels