The button closest to the USB port is the UV side of the light.
With the first click of that button closest to the USB port will cycle through the UV Spectrums in the following order,
UV365 , UV395 and the intense Blue light.
With each push of the button the you will cycle through the spectrums. 1st click UV365 Mid Wave 2nd click UV395 Longwave 3rd click Blue inspection light 4th click OFF.
Then cycling from there.
The other button controls work the same way, cycling through 2 intensities each of: 1st click bright daylight. 2nd click dimmed daylight 3rd click bright incandescent light. 4th click dimmed incandescent light. 5th click bright infrared light. 6th click dimmed infrared light.
Now with SMART features on the natural light side, hold the button down until it flashes, about 3 seconds, and the next click is OFF.
Or if you’ve left it on one spectrum for more than 10 seconds the next click will be OFF as well.