I actually found a link:
http://www.perpetualmarketingonline.com/adcom18.htm
It is what I thought it was.
"ADCOM's XR-500II remote sensor with infrared repeater circuitry extends the remote control capabilities of your main ADCOM system to other rooms or locations. By aiming your ADCOM infrared remote at the XR-500II you can control your entire audio system from a remote listening area."
http://www.perpetualmarketingonline.com/adcom18.htm
It is what I thought it was.
"ADCOM's XR-500II remote sensor with infrared repeater circuitry extends the remote control capabilities of your main ADCOM system to other rooms or locations. By aiming your ADCOM infrared remote at the XR-500II you can control your entire audio system from a remote listening area."