These "filters" are really magnification lenses. They are powered 1+, 2+ and 3+. You can use one, or any combination of them, as they screw together. More lenses, more power. I just stacked them all together for maximum power. Below, is a picture of part of a watch dial, showing the level of magnification and clarity which can be achieved with this relatively inexpensive apparatus. Camera was Nikon N70, 200 speed Kodak color film.
Copper-dial "Tara" watch.