Features: Advanced WDA817B ceiling mounted detectors features intelligent motions detection and 360 coverage, ensuring reliable security monitoring with not interferences 4SMT technology for stable operation in electromagnetic environment. Equipped with double NC/NO alarm outputs and accuracy processing technology, this ABS constructed detectors achieves 8 meter detection ranges while minimizing false alarms through enhances signal analysis capabilities. Ideal for homeowners, business operators, and security professionals requiring multiple zone defenses in residential complexes, retail stores, and industrial facilities with diverse alarm system compatibility needs. Optimally installed in hallways, entryways, or warehouse , this ceiling security sensors continuously monitors 360 degree space, automatically triggering alerts upon detecting unauthorized movement in designated areas. Engineered with strong ABS housing and professional grade components, this motions detectors delivers uninterrupted surveillances performances across temperature varied environment from 10°C to 50°C. Specifications: terial: ABS Diameter: about 82mm/3.2inch Operating electric : 9 - 16 electric Power current consumption: less than or equal to 18 at 12 electric Operating temperature: -10 degrees to +55 degrees Installation method: ceiling installation Installation height: approximately 2.5meters Detection distance: 6 to 8 meter Detection angle: 360 degrees Alarm output: normally closed/normal open optional not -tamp switches: normally closed Package Includes: 1xInfrared motions sensors note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the differences between different monitors, the picture may not reflect the actual colorful of the item.