Go to you name and add them to your system pictures.
Please help identify speaker units
I am currently asked to sell some HiFi equipment for an acquaintance. Amongst others a DIY speaker in a concrete cabinet 
I would like to know what the speaker units are, but as they cannot be disassembled I would need your help to identify one of the units. I have attached to pictures, one of the units seen from the front and a drawing with some dimensions of the units.
The units seem to have a metal membrane covered with a very thin mesh as I hope you can see on one picture. The dimensions are in millimeter.
Can someone please help identify the speaker units?
Thank you.