Here's your choice of round shifter/lever knobs in four different colors.

Use them on Futurattraction's levers as well as their Hurst, Lenco or Liberty shifter sets.

Go with a period correct white or black, or match your interior color, or just be different.

One pack contains 4 round knobs, your choice of color: Black, Red, Blue, Green, and Yellow.

Ball diameter is 3/32", 2.4mm.

These knobs are really small push pins with the metal pin removed, which leaves  a small hole already centered in the knob.

Here is a knob on a Futurattraction Hurst shifter.
They will also work on Detail Master's Hurst shifter set.

Four round knobs by Ted's Modeling, 1/25 scale.