The RCTD-20U from OPTEX is a wireless driveway alert system with an open-air range of up to 2000 feet. It will provide up to three tones from the chime receiver that simply plugs into a wall outlet. You may use up to nine sensors that will provide perimeter awareness for your home or business.
This is perfect to secure entry to any single entrance area, whether it is a compound, acreage, or store-front.