I get that the ToosforHealing one is better, but if you have an F165 you should get the cable so there is no need to buy that zapper...
But for Pandora's box this is very interesting:
Again, we must not demonize the opposite polarization. It is part of us, too, just as the seed belongs to the fruit. But much greater care is needed in handling south pole forces. Notice how Nature has its south pole seed securely encased. Don't do south polarization experiments till you have gained much experience with northerly ones.