THE knob for humbuckers!

If Gibson and Fender use for their high-end models of the CTS potentiometers, this is no coincidence.
These little things have indeed great importance in sound microphones. And CTS have a reputation for being a consistent quality with a narrow tolerance of resistivity.
Generally, the 250k is to be used for single coils pickups (Fender Strat or Tele, P90, etc.) and 500k for double humbuckers coils (Gibson, Jackson, etc.). But it is possible to add their strength to adapt to situations ... which then requires a good knowledge in electronics.
Anyway, even if it seems expensive, these potentiometers can actually positively influence the sound of a guitar, in the sense that they will let pass signal more "pure" (with more clear high frequencies) that metal poor quality potentiometers third category.
But attention to the choice of the model!
In addition to resistance, know that there are linear (constant increase of 1 to 10) and logarithmic (offset increased more adapted to human perception). I prefer the latter models for both the tone for volume, but both types are equally commendable and have no "sound color" special.
Attention also to the length of the rod (there are long and short, depending on the thickness of wood to cross), as well as its form (full or split to plug buttons to buttons with screws).
Last detail: CTS are to US standards and their use in guitars made in Asia (as is often the case) usually require to expand the holes for passing the stem. It's nothing too difficult with a file or a vulgar knife, but you are warned.
Now you know everything.
Happy customizing!