SD Card holder shaped as a volume dial. If you have access to magnets then you can use 4 8X3mm magnets, please see the photo for a self-explanatory description. Just add a filament change to where the magnets go in the top and bottom parts of the model, just remember to make sure your magnets are orientated in the right direction otherwise you might find that your newly printed SD card holder top and bottom parts will repel each other rather than attract each other.
Alternatively, you can just print the model without the magnets.
A short video of this in action, link below.