Coal traffic is big business for the railroads of today, and it's easy to model with these three-packs of WalthersMainline RD-4 Hoppers! Introduced in the 1990s, the prototypes are equipped with both rotary couplers and rapid-discharge bottom gates for quick unloading at any power plant, but can also be found hauling scrap and other bulk loads. These railroad-ready models have a detailed body with separately applied door mechanisms, brake gear and interior bracing. Each rides on a heavy die-cast metal underframe for excellent performance, and includes 33" RP-25 turned metal wheelsets. Two cars are equipped with a Proto MAX(TM) metal knuckle coupler for the outside end, with dummy knuckle couplers on intermediate cars. The perfect starting point for a new unit train or for expanding your current fleet, each set includes three cars in the same scheme with three different, limited-run car numbers, for a total of six cars each - three matching single cars with different numbers are also available separately. Be sure to check out Cornerstone coal mines, flood loaders and power plant kits to model a full range of operations!