Some hardware made by KDS Electronics.
- The Communicator might be a modem (according to a review in the Danish Amstrad Magazine Amstradbladet 1985, Issue 6 page 35). Possibly a revision of the Mini-Max Modem from KDS.
- It might also be a Serial and Parallel interface being made years later in 1992 (according to http://www.retroisle.com/amstrad/cpc/Articles/hwlist.php).
The above descriptions do more or less conflict with each other, the danish article from 1985 sounds a bit more trustworthy, but maybe both descriptions are correct (and the whole package consisted of both a modem, bundled with serial/parallel interface).