4 pairs of Baltimore & Ohio wood beam, leaf spring trucks of a type used in the 1840s and 1850s. Other early railroads used a similar design. This version fits Bachmann Old Timer models. Approx. 48" wheelbase. Made to use MicroTrains or Fox Valley Models low profile 33" wheelsets with .540 (MT-size) axles. Because of their small size and fine detail, Frosted Ultra Detail is the prefered material. Clean with soapy water or alcohol before painting with enamels or acrylics. Use toothbrush soaked in Bestine rubber cement remover if particularly greasy. part number T01b Contact email@example.com for painted trucks with wheelsets.