OCT-ESY SENSE Compact presence detector with its integrated power section controls & Ultra Sense Technology the lights in offices and at other workplaces based on the amount of daylight and the presence of people. So power is only flowing if its needed. The presence detector is surface-mounted to the ceiling and monitors the area below it. If a certain brightness value is undershot, it switches on the connected lighting when movement is detected and switches it off if sufficient daylight or lack of movement is detected.