Tony (and anyone else that should need to know) the size of the inner barrel is the wrong size it should be 2.5 and not 2.1.
Direct from exaSound: "Barrel size for e20 Mk II and e20 Mk III - 5.5mm outer diameter by 2.5mm inner diameter."
Just thought all should know in case there is an issue in the quality of the playback in sound.