Ex broadcast equipment (Logitek USA)

Collet knobs are often used in professional equipment because there is no spline fitting or grub screws which can become loose over time.
Collet knobs have an all metal centre fitting which grips the control shaft tightly and they will not let go!

To access and fit a collet knob … Flip off the top cap, unscrew the central bolt and the knob can then be slid onto or released from the 1/4″ control shaft All metal grip mechanism Red top cap with a Black body – there is NO pointer line because these were used with a continuously rotating control 13mm diameter knob
15mm height