Sound can really bring a layout to life and these new modules make it so easy; just connect two wires to the nearest power source, hide the module, and turn it on. FEATURES: Compact sound module with built-in loudspeaker Real natural sounds specially recorded for these modules Easy connections - just two screw terminals for power supply Power from 8-16v smooth DC for natural random sounds Or power from DCC for controlling sounds by DCC or random Fits inside a model or under the baseboard Built-in adjustable volume control Joint British development between Gaugemaster and Train-Tech