The Azco AZALERT1 Driveway Alert detects movement around your home so that you know when someone is coming up your driveway or approaching your property. The motion sensing transmitter is mounted in the area you wish to monitor. When the sensor detects any sort of motion from people or vehicles, it will send a wireless signal up to 200 feet to the receiver. The sensor can be used on the porch, the back yard, or on a shorter driveway. The receiver is placed inside and when transmitter detects movement, the receiver plays a pleasant chime to alert you. The chime volume is adjustable volume to suit your surroundings. The Driveway Alert receiver is powered by 3 ‘C’ batteries and the sensor is powered by a single 9V battery (batteries not included). Set up is so simple, you can have it up and running in 5 minutes as a DIY solution. ** Range is based on clear line of sight without obstructions.