This is an adapter to fit an aftermarket shiftknob on the stock shifter.
The adapters that came with the shiftknob didn't have a ring to hold up the shiftboot, so I designed one with a ring attached so the leather shiftboot will be held up.

It is designed to work with a mishimoto shiftknob, but might work with others.

Included are 3 sizes:
M8 X 1.25
M10 X 1.5
M12 X 1.25
These are the inside diameters to fit on the shifter