The Model 911 Emergency Drive-Thru System will keep your drive-thru operation open even when your installed system is down. The inexpensive 911 system comes ready for easy hook-up and is conveniently packaged for storage. When service is interrupted, simply place the base station on the counter at the drive-thru window and hook the outdoor speaker on the menu board. Run the provided speaker cable between both units and plug the transformer into a wall outlet. Complete the installation by placing the air detector hose over the driveway in front of the menu board, and you're back in business. Setup takes less than 10 minutes.