The Protech by Hirsch SDI-77XL2-B PIRAMID XL2 is a dual technology outdoor intrusion sensor featuring a medium-angle Lens B that delivers a precisely focused 100 ft. x 35 ft. (30 m x 10.5 m) volumetric detection pattern. 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 wind, rain, vegetation, and temperature fluctuations. The medium-angle coverage is ideal for protecting moderately wide open areas, loading zones, building perimeters, and equipment yards where broader coverage than a narrow corridor is needed but tighter focus than a wide-angle pattern is preferred. Powered by 10 to 28 VDC with a rugged IP65-rated aluminum housing, 10-position digital range and sensitivity controls, balanced temperature compensation, and Stereo Doppler supervision that locks the sensor into alarm upon any component failure, the SDI-77XL2-B delivers false-alarm-free performance across the most demanding outdoor environments. Operating from -40°F to +158°F (-40°C to +70°C), it is built for year-round, all-weather perimeter protection.