Thanks for looking. Offered is a Good Used Reverse Unit for Marx 666 and 1666 Locomotives. We happily combine shipping. Marx reverse unit from a 666 / 1666 double reduction locomotive frame. Unit is in good condition and works well. Ready to install. Watch for additional parts and spares being listed, as I am cleaning out some of the excess parts I’ve accumulated over the years. Item weighs under 1 pound packed for shipping.