This official PRS 270K Silver Sky Guitar Volume Potentiometer is designed with a custom taper and made by industry leaders CTS. Due to PRS and John Mayer's exacting tone requirements, each Silver Sky volume potentiometer is measured to find its true resistance value after tolerance (potentiometers have a tolerance which means the final resistance value can be above or below the stated value of the pot) PRS then select a fixed value resistor and solder this to the pot, the value of the fixed resistor is chosen based on the pot's true value so that when they are soldered together the resulting resistance value of the volume control will be much more accurate. The imperial threaded short shaft is useful when mounting to scratchplates or control plates to ensure the knobs do not sit too high above the body, both the threaded shaft and knob mounting shaft are made from durable brass and it has fine 24 spline mounting for imperial sized knobs.