The Legrand 048817 Mosaic presence and natural light detector saves energy by only switching lights on when there is insufficient natural light and human presence in a room.

Lighting is permanently off when natural light is sufficient, regardless of presence
Automatic switching
Precise adjustment on-site with configurator setting
Adjustable time delay: 5 seconds to 59 minutes
Brightness threshold adjustable: 5-1275 lux
Double IR detection 360°: lateral range 2 x 12m
Optimal distance between detectors: 20m
Installed directly into a false ceiling with included hooks
IP20
ECO2

Ceiling mounting hooks

Daylight Lighting Controllers

These controllers automatically turn lights 'ON' and 'OFF' in response to changes in ambient light levels, primarily the transition from day to night and vice-versa. The more advanced types (see note below) have inbuilt logic to minimise false triggering, whereas the remainder have inbuilt time delays or higher 'OFF' thresholds, to prevent on/off cycling. As a general rule, these controllers should be sited such that they are not illuminated, by the light they are controlling. Nominal supply voltage is 230Vac.,Note regarding energy-saving negative-hysteresis controllers,Where figures for the 'OFF' threshold are lower than for the 'ON' threshold, the sensor is designed such that four thresholds are actually monitored. These are: dusk, the middle of the night, dawn and the middle of the day. Monitoring at times other than dusk and dawn enables the sensor to determine what it should be looking for next, minimising false triggering and improving overall controller operation.