There is a little clip on it with a plus sign. You attach the F165/zapper's Positive alligator clip onto this. Run the frequency 1000 Hz (or whatever really, as long as its at or below this.)
Then you go over the lymph nodes with it. Couple notes:
-Do NOT go near the heart, brain, or genitals. They are supposed to be south polarized, always, and messing with that can seriously screw you up.
-Magnets are detrimental when you are chelating. I would say, judging from recent experiences, that the magnetism can actually pull metals out of their bonds with ALA/DMSA. So don't use a zappicator (or any magnets) on yourself if you are chelating. Do it during a break.
-The liver is an amazing place to zappicate as long as you stay away from the heart. I experienced improved hair growth and quality of hair (it feels silkier) after zappicating a specific spot on my liver. As I moved it around the organ, I felt different effects all over my body, but all very pleasant - it confirms the fact that the liver uses different areas for different toxins.
-My second favorite place to zappicate/pulse is the back of the knees.
Hope this helps.