Unlimited sensors and transmitters may be used with the new wireless series of Drive-Alerts to monitor several areas. The sensor is encased in a durable outdoor metal enclosure. They monitor a 14 foot radius (28' diameter). These sensors run on two standard AA batteries which will last more than a year under normal usage. These vehicle alert sensors may be placed up to 1000 feet from the Control Panel, and up to 2500 feet when used with the DA-660. The sensors are tamper resistant due to the fact that if anyone touches or moves one, the alert will be triggered.