Maybe it would help if I told you where I got it. At the alabama-Coushatta Indian casino in Livingston, TX. They had a set of these slot machines that would only work when the house had one of these in a special slot. If you pulled it out an alarm would sound and the flashing lights would start. Their slots did not have player card capability. The gold looking square at the top is a small cicuit. I was there on the last day and a number of these machines were out of order so I did what came natually for a collector. the back reads as follows:

"TREAT AS CASH -DO NOT THROW AWAY

The Propriator will not replace lost or stolen cards.
Machine malfunctions will void play, and propriator will not be responsible for any credits lost as a result thereof.
Proof of ID may be required for reimbursement of credits.
The propriator will not be responsible for any credits lost that are not played or redeemed with in 60 days.""