The first reference in the video is to the familiar roller stripe gauge (ruler) that measures the thickness of the roller pressure setting or stripe on the plate. You can get this for free from ink and roller suppliers.
The second reference is the one you are asking about.
You have to purchase this from your press manufacturer.
Instead of looking at the plate, you print a dry solid, and lay the film "foil" over it. This method is more messy if your inks are still wet.