Keep track of vehicles entering or exiting your property with the Mighty Mule Driveway Alarm. http://www.costco.com/Browse/Product.aspx?Prodid=11759613
The MightyMule Wireless Driveway Alarm detects vehicles entering or exiting your driveway and alerts you with an indoor time. The MightyMule Wireless Driveway Alarm provides perimeter security by notifying you when guests or unwelcome visitors drive into your property. The Wireless Driveway Alarm is easy to install and includes the vehicle sensor, transmitter, and indoor base station. This reliable driveway alarm has a wireless range up to 400 feet, and it will not be activated by people or pets-- only moving metal objects. Not only is the Wireless Driveway Alarm a dependable addition to your home security system, it makes a perfect gift for loved ones. The MightyMule Driveway Alarm, on guard 24 hours a day.