The Protech by Hirsch SDI-77-MW PIRAMID Indoor Microwave Only sensor delivers precision volumetric intrusion detection across a 100 ft. x 60 ft. (30m x 18m) coverage area using Protech's proprietary Stereo Doppler Microwave technology. Engineered as a single-technology microwave sensor for indoor environments where the highest level of detection reliability is required, the SDI-77-MW features two independent receiving channels that intelligently discriminate between genuine human motion and non-threatening sources such as vibration, swinging signs, and HVAC airflow. Ten-position digital range and sensitivity controls allow precise field tuning of the detection zone, while the rugged metal housing provides superior RFI and EMI shielding. Operating on 10 to 28 VDC with an X-Band 10.525 GHz frequency (USA), this sensor is purpose-built for high-security indoor applications including military installations, government facilities, data centers, and correctional institutions where microwave-only detection is specified or preferred.