LUX knob: The sensor’s response threshold can be infinitely varied from 3-2000 lux. Control dial set Daylight operation approx. 30-2000lux. or turn the LUX knob clockwise on the sun position (Adjust according to ambient light). Control dial set Night-time operation approx. below 10lux. or turn the LUX knob anti-clockwise on the number 3 (Adjust according to ambient light).