The professional choice in outdoor protection, our Quad beam detectors synchronise 16 beam paths for maximum stability in severe weather conditions, perfect for long range perimeter protection. For distances up to 50m (165ft) outdoor / 100m (330ft) indoor. Synchronised Quad Beams for maximum stability in severe weather conditions. Double Modulated beam for unsurpassed immunity to direct and reflected sunlight, vehicle headlights and other light sources.. Built-in view finder and monitor jack output for easy beam alignment. 180 degree rotating optics for increased installation flexibility. Automatic Gain Control circuit.