Is this the world’s smallest ribbon microphone mechanism?
The Beyer M560n(c) has a motor measuring just 33 mm long and 10 mm deep, which fits into the mouthpiece of a headset.
The tiny transformer is mounted at the other end of the microphone. The mic is clearly designed for close speech and the transformer has a very low inductance (35 µH at 1 kHz), which gives a bass roll off to compensate proximity effect.