The Protech by Hirsch SDI-77XL2 PIRAMID XL2 is a dual technology outdoor intrusion sensor equipped with the standard wide-angle Lens A, delivering an expansive 90 ft. x 50 ft. (27 m x 15 m) volumetric detection pattern — the broadest coverage in the XL2 lineup. Combining PROTECH's proprietary Stereo Doppler microwave technology with passive infrared sensing in an "And Gate" configuration, both technologies must activate simultaneously to generate an alarm — virtually eliminating false alarms from vibration, wind, rain, vegetation, and temperature fluctuations. Advanced signal processing with special filtering provides exceptional immunity to birds and small animals, while the Stereo Doppler Supervision feature locks the sensor into alarm upon any component failure for maximum security integrity. With a wide-angle H 60° x V 60° field of view, the Lens A pattern is the ideal choice for protecting large open areas including car dealerships, equipment yards, lumber yards, utility substations, correctional facilities, and military motor pools. Powered by 10 to 28 VDC with a rugged IP65-rated aluminum housing, 10-position digital range and sensitivity controls, balanced temperature compensation, and an operating range of -40°F to +158°F (-40°C to +70°C), the SDI-77XL2 delivers false-alarm-free performance across the most demanding outdoor environments.