The Protech by Hirsch SDI-77XL2-D PIRAMID XL2 Dual Technology Sensor with Lens D delivers precision vertical barrier detection across a tightly focused 100 ft. x 10 ft. (30 m x 3 m) corridor pattern — ideal for protecting narrow passageways, gate entries, building perimeters, and fence transition zones where a concentrated detection field is critical. Combining Protech's proprietary Stereo Doppler microwave technology with a dual-element passive infrared sensor in an "And Gate" configuration, both technologies must activate simultaneously to trigger an alarm — virtually eliminating false alarms from wind, vegetation, birds, and small animals. Powered by 10 to 28 VDC, the SDI-77XL2-D features 10-position digital range and sensitivity controls, balanced temperature compensation for consistent performance from -40°F to +158°F (-40°C to +70°C), and Stereo Doppler supervision that locks the sensor in alarm upon any component failure. Housed in a rugged, vandal-resistant aluminum enclosure rated IP65 with an integrated weather shroud, this sensor mounts via a swivel bracket with 180° horizontal and 90° vertical adjustment for precise aim of the vertical barrier pattern. Deploy the SDI-77XL2-D wherever a narrow, deep detection curtain is required — from utility substations and chemical storage facilities to correctional perimeters and military installations.