Old 1980s Echo Module

[Maruefer]

wondering if anyone remembers the old echo modules that were fully encapsulated in black plastic so you could not copy. Found one in old C2k but the wires beyond black and red are faded and those were actually cut. Could try and find but thought to ask first if any old guy (like me) has any info from that era laying around and would not mind sending my way

thanks
mark