The HP-41 family card reader (HP82104A) is a very useful accessory for storing and retrieving programs and data. The card reader presented here is in excellent condition, in original box with its manual. The device is recognized by the calculator as seen in the images. It comes with a number of used cards which will be very useful when testing it.
Why would it need testing? Because the device is most likely affected by the “gummy wheel” issue (at least) so it will probably need repairs. I have not seen original card readers that still work without repair after 40 years, and I doubt this one is an exception. The serial number shows it is made in 1980 in Singapore.
The card reader does not show signs of being previously repaired. Both retaining tabs are in good condition and there is no rattle inside, both of these are common problems for this type of device.
The device was tested in a HP-41 to show catalog, the calculator used for test is not part of the package.