Genuine CTS pots, the brand used by nearly every American guitar company for half a century!
500k 10% audio-taper, mimics the logarithmic way humans perceive changes in volume better than any other taper.
1/4" solid-shaft, designed for knobs with setscrews and 1/4" holes (metric knobs from imported guitars will not fit).
3/8-32 bushing thread is 3/8" diameter, 1/2" long. For rear-routed guitars, this bushing length provides enough threads to pass through the guitar's top and still allow for hardware installation.
CTS low torque design (dimpled back) is easy to turn, this is the style used on Fenders since the 1950s.