SK901         Popular USA dual light switch sensor save energy sensor

The  wall switch occupancy sensor,is designed to replace the normal ON/OFF wall switch.It will detect motion from any heat-emitting source(such as a person) within its field-of-view(the area of surveillance).After the primary detector(PIR) senses presence and engages then microphonics(the sound detection system) comes into operation to keep the status of the detector as "Occupied" even though there is no detected motion but if any sound.The controlled lights will remain ON until no motion/sound is detected and the pre-set time-delay has expired.