Be prepared! The Driveway Alert System lets you know someone's arriving -- from up to 1/2 mile away. This driveway alarm gives you extra time to prepare for unexpected guests, plus it can be used to monitor your property. Just mount the Driveway Alert System's motion sensor on a wall or post. When motion is detected, the driveway alarm sensor transmits a radio signal to the in-house receiver which uses both light and adjustable sound to warn you that a vehicle or pedestrian is approaching. With the Driveway Alert System, you can add up to 3 additional sensors to monitor 4 different locations with the same receiver. This driveway alarm also features adjustable sensitivity controls to help prevent false alerts. The Driveway Alert System includes an in-house receiver powered by AC adapter (included), plus an outdoor sensor that requires 4 AA batteries (not included). Benefits of the Driveway Alert System: Use this driveway alarm to monitor your property at home or on a worksite Both wireless and weatherproof, the Driveway Alert System works from up to 1/2 mile (2,640 feet) away Driveway alarm alerts with both light and sound when someone arrives Driveway Alert System will not be triggered by small animals passing by