I have it since 2015, day and night armed, and until today it hasn't failed me. It's not Chinese, it's Korean, maybe that's why it still holds up. It has a volumetric feature that you can adjust as much as you want, it hits with seismic force and has very good sensitivity. It has intercom control and the truth is that it saved me two or three times when someone tried to break into my car, once to steal gasoline and the other two times to break into it. The alarm went off and the remote control also alarmed that the car was being violated. It has been tested up to 500 meters of armament and disarmament