Does anyone know what this keyboard adapter is for?

[Al Kossow]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7530768047

I asked the seller what the gray pigtail was for and how you
would use this with a 16500, and as usualfrom an eBay seller,
got no reply.

I have several of these, and when I opened them up they are
completely passive with no connections between the PS2 and
HIL connectors. The pigtail plugs into a 10 pin RJ style on
the back, and the other three connectors run over to it.