The LM-3S-21 RailPro HO Scale Locomotive Module with Sound and 21 Pin Connector is the Railpro module the world has waited for.
 
- Direct Radio RF transceiver built in
- Up to 12 Light Outputs capable of downloadable light effects
- Downloadable sounds and much more
- Tiny size for easy installation
 
Additional information: https://www.ringengineering.com/LM-3S-21.htm