[Coco] Looking for The CoCo Coupler CP/M

[CoCo Demus]

Hi, I am looking for a specific hardware I believe is a cartridge.

The Rainbow October 1984 page 232 shows The CoCo Coupler CP/M which has a
Z80 to be used with the coco 64K and access CP/M.

Does anyone have any piece of information or this hardware ? I would like
to clone it. It would make a nice pair to the WordPak RS and even maybe add
OS-9 support to it.

Thanks,