404LE:
18.5mm diameter but there is a keyway that sticks up about 1.5mm tall in addition to that diameter
Keyway starts 3mm from plug end otherwise depth before "cable start" is 17mm
So you need < 17mm depth and > 21.5mm diameter, best I can tell.
I don't like things to stand out too much. It just caught my eye. The all black look with only the white stitching and markings to give it a little pop. Just a very well integrated look IMO.