This is a microphone flag to be used with regular handheld interview microphones.
I have tested it with my Shure Beta 58A microphones, but it should easily fit many other vocal/interview mics.
The OpenSCAD file is made so that it is easy to change the size an shape to fit more or less any logo or name that you would want to put on it.
I have also attached a few different STL files, for those that don't want to bother with OpenSCAD and just want a standard flag.

I have been printing these as they appear in the STL files (only moved up to sit on the platform). There is a large overhang section when doing it this way, but the bottom part of the overhang (where it won't be perfect on machines without support material) is inside the flag and will be covered with foam.
If you have trouble printing these flags as described above, you could move the top plate with the cutout for the microphone up to be flush with the top of the walls, and print it upside down (simple edit of the SCAD file).
After you have printed the flag, cut out a piece of foam (I prefer dark grey foam, but it doesn't really matter) to fit snugly inside the flag.
Lastly, cut a hole middle of the foam that fit's your microphone, but make sure it's not too big, it needs to be tight enough to hold the flag on the microphone.
If you want a different size, simply open the SCAD file and change the values in the function call in the bottom of the file.
The measurements are mm and specifies the size of a single side of the flag. This way it's easy to customize the flags to fit existing stickers with your logo.