My buddy "needed" a monacle so I came to Thingiverse to download and print him one...but did not find it!

40 minutes later I had this one designed, and decided to share (since Thingiverse was lacking this).

All its size parameters are defined at the top of the OpenSCAD source. If it does not fit your needs/face, you can modify the settings and regenerate the STL.

I have included GCODE for PLA/0.15mm if you're feeling adventuresome & don't want to slice it yourself.