The Dakota 2500 alarm products are the newest in their long line of driveway sensors and alarms. Each 2500 series sensor/transmitter has a wireless transmission range of 2500 feet line of sight. This generally translates into a wireless range of about 1500 feet in "real world" (trees, buildings etc. as obstructions) applications. These are very reliable wireless driveway alarms and with the unlimited number of units which can be used in one system the Dakota Driveway Alarms are sure to fit almost any application.