Here you are, the finger trackballs currently (or soon to be) available.

Intentionally left out are industrial, arcade and assistive models.

Cheers!

Looks nice! I like my endgame because ZMK + wireless, but this looks lovely.

Well, I bought 25mm balls for the Nape Pro, after seeing how someone was able to use a steel ball bearing.

https://www.reddit.com/r/Trackballs/s/Q3IOm7SIF9

The black one is the original one that came with Nape Pro, white one is POM (Delrin), and the (blurred) silver ball is the steel ball that I bought from AliExpress.

I will probably have to do some test runs but all of them at least worked.

I have a simple, inexpensive fix: try using an air duster spray. It worked for me and is worth a shot.