This is a 0 degree GoPro Session 4 / 5 mount for TBS ND filter.
It fits ND16 filter that is 2,5mm thick.
There are 2 cuts at the bottom of the mount for a quick filter swap.
Superview friendly :)

Edit:
Changed to version that also fits ND8 and ND4 filters, they were a bit loose in the previous mount.

Prusa

Prusa Clone

Yes

0.2

50%