why do some hum pickup covers have holes in them for what appear to be screws? i want to replace the covers on my to make it a little more cosmetically original and to my liking, so i figured id ask before i order the wrong things. thanks.

ps. on a les paul, the plate under the switch that says treble and rythem, what is that called so i can search for a different colored one, and how do i get it off? thanks again.
the holes and are for screws which can be adjusted for tone purposes some humbuckers have em that you can adjust just figure out what kinda pickups you got and that should help you decide what covers to use, to find that rythem treble cover go to


if that doesnt suit your needs they are called toggle switch plates just google it
i do have ones with the screws, do i absolutely need to get one with holes or can i just cover them with a plain cover (i dont use the screws at all) or will they not fit right. how easy is it to replace the screws so i can change them to match the color scheme im doing?. and i found the switch plates, thanks.
i think you can cover them but i myself wouldnt but maybe someone else will hve a more detailed reson why
I know there is a difference in sizes on the covers. And usually you have to fill em with wax or they will pick up alot of microphonics. The switch plate on a LP is just stuck to the guitar. Theres usually only 2 colors you can buy black or cream.