MSD Retard box

This will show all of you nice folk how dumb I really am.
4 posts after my initial Q. and I yet to understand anything.

Please in layman terms...
Will I need any chips for this machine or are they already in this box ?
Seeing it has a dial already stationed with numerical positions on the face of the box for you to just go to the actual retarding you need (or, in my case, are, lol)
Or are the numbers just there to show you this is were you need to position the dial to get the timing you want, now that you have the chips (installed) in their designated area. With the advantage of having a multitude of degrees you can use... Because/With these chips/modules.
Compared to the other boxes I've seen that seem to be digital and have 2-3 degrees positions you can retard the timing by just turning the dials on the back of those machines?

Thanks waaaaaay in advance.