Receive an alert every time a vehicle enters or leaves your driveway with this battery-powered wireless driveway monitor from STI. The device uses a solar powered patented magnetometer sensor system and comes with a 4-channel voice receiver that gets a signal every time any large metallic (iron or steel) object comes close to the driveway sensor. The receiver sounds a programmable voice message using 10 tones/tunes and 53 word options. Operates up to 1000 feet (305m) from the receiver in your home. People, animals, and shadows will not trigger the sensor. Perfect for rural properties.