The Protech by Hirsch SDI-77XL2-EX-IND PIRAMID EX Indoor Stereo Doppler Motion Detection Sensor delivers explosion-proof intrusion detection purpose-built for indoor hazardous locations where flammable gases, combustible dusts, or easily ignitable fibers are present. Featuring Protech's proprietary Stereo Doppler microwave technology with two independent receiving channels, this sensor eliminates vibration and periodically moving objects as sources of false alarms - delivering reliable, false-alarm-free performance in demanding industrial environments. The indoor-specific software provides higher movement sensitivity optimized for enclosed spaces, plus an optional PCB for fluorescent light noise filtering to prevent nuisance alarms from industrial lighting. Housed in a rugged IP66 the SDI-77XL2-EX-IND covers up to 100 ft. x 40 ft. (30 m x 12 m) and operates on 10 to 28 VDC across a wide -40°F to +158°F temperature range. Approved by the USAF for Protection Level 1 Nuclear & Below and certified for Class I Div. 1 & 2 (Groups C, D), Class II Div. 1 & 2 (Groups E, F, G), Class III, and NEMA 4/7BCD/9EFG, this sensor is the definitive choice for petroleum refineries, chemical plants, processing facilities, and other high-security indoor hazardous environments.