Matched Sets (Pairs / Quads) for 550 kΩ available here.
These are NOT the same CTS pots that many companies stock and sell. These are developed using 9% +/- tolerances and a value at 10% over the standard 500K rating (550K). This ensures you not only optimum performance but guarantees your potentiometers will always be at least the value stated unlike many others using 20% tolerances where you can be over spec but in most cases way under the specifications you need to ensure good tone from your pickups. Brass components and a high quality wiper were added versus what comes standard on most run of the mill pots to ensure long life, quality and consistent performance.
These potentiometers have a Modified 20% Audio Taper which is suitable for both Volume and Tone positions.