MOBILE DECODERS ARE DECODERS TO INSTALL IN LOCOMOTIVES. Some decoders are "hard-wired" wire by wire into your locomotive by soldering them in. Other decoders are the "drop-in" style and some are simply plugged in with a factory installed 8-pin or 9-pin plug.
5+ MOBILE DECODER DISCOUNT: Buy 5 or more mobile decoders (non-sound) at once and receive a $.50 discount on decoders priced under $25 and a $1.00 discount on decoders priced over $25.