Mighty Mule Wireless Driveway Alarm (FM231)
Wireless driveway alarm, electromagnetic technology detects vehicles entering & exiting driveway & alerts you with indoor chime, up to 400' range from indoor receiver to driveway sensor, does not detect people or animals, transmitter requires 2 "aa" batteries, not included, note: use lithium alkaline aa batteries in colder climates, sensitivity adjustment 3' to 12' radius, dip switches for personalized transmission Codes..
Keep track of vehicles entering or exiting your property with the Mighty Mule Driveway Alarm. (FM131) When a vehicle passes the sensor, the receiver emits an audible tone. Easy to Install and stake is included in kit. The electromagnetic sensor will sense large metal objects and send a signal to the interior base station to let you know someone is there. Install the batteries, near the installation site so the sensor can "learn" the area. If the batteries are installed in the home; the unit may not function properly.

Mighty Mule Interior Wireless Driveway Alarm Additional Base Station (FM231-R), Black
Add this additional receiver to the Mighty Mule wireless driveway alarm (model# fm231wb sold separately). this additional receiver will announce the arrival of a vehicle by a chime and LED light. This receiver also features a low battery indicator light, notifying you when the 2Aa batteries (not included) need replacing in the outdoor receivers.