I've done some research on these and I'm finding out that these promos made by Readers Digest are nice display models-but the couplers are shaped somewhat differently from Rapido couplers, so they do not couple well. Another problem is that the wheel flanges are not shaped correctly for running on N scale.Will not be able to couple these cars to regular N scale cars and run them on layout.So with these issues I'm sorry but am no longer interested.