The Interviewer Light Clamp attaches to the Watch Box and holds your Interviewer Light in place. As an added bonus, this clamp (in tandem with the Front Light Arm Clamp) provides a metal surface which you’ll need for a pair of magnets. You hang the black microfiber cloth on the back of your Watch Box using the two magnets and the two metal clamps, and this darkens your Watch Box. A dark Watch Box creates a superior reflection, as you’ll see in a separate video.