This device is mainly used indoors, adopts infrared detection + intelligent volume recognition technology, can effectively prevent pet interference and false alarms, and is mainly used in pairing with the wireless 433MHZ signal of the alarm host. When the device detects an intruder, it immediately transmits the wireless 433MHZ signal to the alarm host. When the host receives the alarm information, it is easy to install and does not require wiring. It is mainly installed in halls, windows, garages, shops, shopping malls, banks, companies, finances, schools, and other defense areas.