I wanted a gridfinity hex bit holder, there are a few available on Printables but none that quite had all of the features I wanted. I found the closest I could and remixed it to make it stackable.

In gridfinty language this is 2x2 and 6 units high

Holds 64 6.35mm hex bits. The holes are a touch loose but this means they're easy to remove. There is clearance for 25mm long hex bits before stacking more gridfinity modults on top becomes difficult. If you don't need to stack, please make sure to check out the original model that I remixed.

NOTE - If you have already printed the non-stackable version @GustavoTeixei_380523 has created a height expansion you can use to “upgrade” it - https://www.printables.com/model/426673-gridfinity-2x2-raise-height-expansion

excuse the gaps in the my print, I think it's an Arachne thing…