Robo Guard

The roboguard is a stand alone, wireless automatic outdoor intruder security system using passive infrared sensor beams that detect movement up to 20 meters away in an 110° arc. Each guard has two sensors one on top and one at the bottom, each emitting 11 beams, a top and bottom beam have to be broken within half a second to trigger an alert. This effectively eliminates false alarms caused by dogs, birds and plants.

http://www.roboguard.org.za