Stem size and the hole size. I printed them in pla, but final versión was printed on resin, super detailed and smooth texture. In my opinion, this kind of hat should be printed in resin for super high quality.

nice one, thanks!

I'm pretty new to 3D printing, haven't remixed any designs yet myself.

Was it just a matter of adjusting the stem length or was there more to it?

I have not my files any more but I did remix [this one](https://grabcad.com/library/alps-rkjxm1-hat-caps-and-mounts-1) to work with VKB.  
Hope it helps you!

Gladiator NXT replacement custom HAT caps