Speed Knobs - Metric  18 Spline

-  A Metric Guitar Speed Knob is a common type of control knob specifically designed to fit the standard potentiometers
    used on most imported and non-USA made guitars. These knobs are made for the metric-sized pots, which have a
    shaft diameter of 6mm. They are designed to fit a coarse-spline (coarse-knurled) split shaft, typically with a count of
    18 splines on the inside of the knob. Commonly found on most Asian-made guitars (China, Korea, Japan, etc.) and
    models from brands like Epiphone, Ibanez, ESP, and others that use Alpha pots or similar import hardware.