Double Middle

-No Magnets
-Double the long bit storage

I printed the original "Bit_Holder_20slots_Left_Right" file with flexible PLA filament at 94% scale so bits would be held with friction.

I then took the "middle Add-On" and mirrored the bump out to allow for twice the Add-On long bit storage capabilities. Printed with regular PLA at 94% scale for a solid carabiner attachment point

The "Add-on" I printed at 100% scale with rigid clear PLA because I like the magnet functionality for this part. This makes the sides slightly overhang the Left and Right pieces, but barely.

You can skip magnets altogether though if you print the Add-On with flexible PLA at 94% scale

Or just print the double middle piece as normal for extra storage on your bit holder