Bachmann 63569 N Scale EMD GP40 Diesel Alaska ARR 3009 TRX4 non looped horn 1 alternate horn non looped horn 1 alternate horn for locomotives with a second horn 4 Times Expanded Autopilot storage Expanded Startup and Shutdown sequences 2 Watt Audio output 84 db signal to noise ratio 16 bit audio resolution 24 sounds with separate volume control Unmatched frequency response as low as 20 Hz when paired with Rolling ThunderTM subwoofer kit 8 simultaneously playable audio channels Functional Dynamic Brake with Grid Blower sounds Improved motor control in DC and DCC Motor short circuit protection Works with NMRA standard DCC controllers Automatic Dual Mode: Works with DC power packs or DCC NOTE: Road number may vary from picture shown 8 cross spans Bachmann 63569 N Scale EMD GP40 Diesel Alaska ARR 3009 25" radius curves or greater