Summary

I needed an adjustable vent for my terrarium. I used a stainless steel M3 screw and lock nut to fasten them together.

It's designed for 3mm thick glass with a 20mm hole.
I made a second version for 6mm glass, but you could always elongate the base thicker to fit a different size.

I later made a bigger terrarium vent that uses a M5 screw and 60 mm hole marked LARGE