Alpha B250K Concentric Stacked Dime Size Barrel Potentiometer 
6mm top shaft, 8mm bottom
Threaded bushing is 3/8" diameter x 3/8" long
Overall length is 1 3/4"

Traditional mini dime-sized pots, stacked! Independent radial controls for both knobs. This thing packs a huge punch in a small space.
250K works perfect for single coil pickups

Standard ±20% resistance tolerance.

High quality, made in Korea