Model Rectifier Corp, AA333, Sound N Power 7000

 Power your layout and add realistic steam or diesel sound with one easy-to-operate pack. Select the sound of your choice, synchronize the sound to the speed of your locomotive and adjust the volume, it's that simple. The power pack delivers 57VA for HO/N Scale and features momentum switch, pump action brake switch, on-off power switch and 300° throttle control. Provides enough power for up to 6 average HO trains. An 8 ohm, 4" round speaker and 12' two-conductor cable are included.