This is a simple gridfinity holder for a 5C collet block set.  It has spaces for the square block, hex block, ring and clamp.   It uses a 3x3 grid.

The model shown is printed with eSun PLA+ Bone White for the base and a 1.5mm lip at the top using Polymaker PLA Pro Metallic Chrome for a contrasting accent.  This was done with a layer height modifier for the last 1.5mm.

Here's a list of what's used in the holder:

• 5C collet block set