I needed a way to keep ONE micro sd card in storage.
Here are 4 micro sd boxes and tops on a common brim.

I made an addition:

I added a full size sd box.
This sd box was a total redesign.
Depending on how well your printer prints you will probably need to clean it up inside with a razor blade due to strings and blobs. The 2 halves fit together pretty snug. Keep scraping with a razor blade until they fit nice but can come apart without breaking.
Here is one bottom and one top on a common brim.
I also added one micro sd top and bottom on a common brim.

Printed in PLA .2 layer 20% infill

REVISION

It has been brought to my attention that the top fits too loose on the full size sd box.
I checked out some of my old prints and sure enough, some of them were a little loose.
So I modified the top a little. It fits tighter now.

I added 3 stl files.
sd box and brim R1 is the complete box, top and bottom on a brim.
bottom is just the bottom and top is just the top.

I printed these in PLA and I had to scrape the corners of the tall thin walls with a razor blade to get them to fit together. Then sliding them in and out a few times loosens them up.
I printed this in ABS and I had A LOT of scraping to do. I eventually used a dremel.
So I think some of this depends on how well your printer is set up with retraction settings. Obviously The printer I use for PLA is dialed in a little better than the printer I use for ABS.
Watch your retraction and scrape away!
Printed in PLA .2 layer 20% infill
Printed in ABS .2 layer 20% infill