? Early cabooses that were built brand new rather than adapted from old box cars and the like, were often small and rode only on four rigid mounted wheels, unlike the more common set-up of two sets of four-wheel truck assemblies. Most likely because of the ride quality delivered by this rigid wheelbase, these types of cabooses were quickly nicknamed "bobbers." They may not have been the most popular style of caboose used by railroads, but they have probably become the most famous of the cabooses. ? The Silver Series(R) models feature blackened metal wheels, body mounted couplers, nonmagnetic axles and superb detail, making them a natural fit on anyone's HO Scale layout. ? ?