Double Router Collet Holder
This is designed to holder router collets for most routers that can handle 1/2 inch and 1/4 inch bits. It does not need supports if printed on its back. I printed it with a 0.2 layer height, 6 walls and 25% infill but don't think the print settings are critical.
It attaches to a surface using 2 #8 wood screws.
I included the Fusion 360 source file and welcome remixes.
You can see a few other designs I created for my router table, including the JessEm Mast-R-Lift 2 Tool Holder (https://www.thingiverse.com/thing:5959486).