Why don’t tattoo supply companies give more info about coils?

Do not be afraid to ask for specific caps when you order prewired
coils. Or you can order coils that have no capacitor at all,
and you can add the preferred size yourself. It is very simple to
solder a cap to the coils. It is also important that you own a solder
iron and are aware of the right types of flux for soldering with
silver bearing solder. Check with your electronics supply stores,
or professionals to get the same quality stuff that they use on
circuit boards and stay away from thick paste flux, typically used
in pipes.