Found toward edge on obverse side near blue extraction clip
Found stamped in raised type on lower lip of blue plastic clip
overall: 5 1/4 in x 5 in
This is a circuit board with a printed copper circuit. At one end is a blue plastic pinned interface with a hinged clip. "HI. PHYSIKALISCHES INSTITUT LEHRSTUHL B T.H. AACHEN" is printed in copper to the lower right of the clip. "Cable Connector card" is printed at the top left edge of the board.