I use a Sena unit. They make several models and it depends on the helmet which might work best for you. The microphone in mine is velcroed between the liner and the shell and on other models it is clamped to the shell along with the clamp for the unit mount.

Thanks John Mat, that’s helpful

In our case, we use the Cardo Freecom 4+. Very happy with them.

If you're curious for details follow the link https://www.speedymarmots.com/works-4-helmets-intercoms/

Donald, my M3W came fitted with the Starcom system and included two headsets that plug into the sockets on the transmission tunnel.
I'll take a pic of them if it's any use.

Just trying to imagine how the Morgan headsets look like

Morgan electrics, two soup cans and a string 😊

You can use the Starcom system with headsets or helmet:
http://www.starcom1.com/kitcar-handsfree-systems.html

I see you specified the 'compact' version

that is some groovy shirt he is wearing

Starcom1 can use both in helmet and stand alone ear pieces with microphone. They are a plug in job.

I much prefer my Scalarider Q1 Bluetooth headset.