Cartell’s Driveway Alarms Wireless harnesses cutting-edge magnetometer technology to sense only moving steel—no motion, heat, leaves, or wildlife can trigger a false alert. It monitors Earth’s magnetic field with precision and alerts you only when a vehicle, traveling at least five MPH, disturbs that field. This alerts you only when a car approaches your driveway. With reliability, vi... https://shop.cartell.com/product/cw-con-wireless-driveway-system/