The product is a pet-immunity passive infrared detector with high stability. It adopts advanced signal processing technology, providing super high detection and anti-false alarm abilities, and MCU processing ensuring the reliability from the design basis. When an intruder passes through the detection area, the detector will detect the movements of human body automatically. If any movements, it will send alarm signal to the connected alarm host. It is suitable for safety protection in residential houses, villas, factories, shopping malls, warehouses and office buildings etc.