You have to cut into the back cover with a knife to retrieve it.
Jack White is the king of strange, novelty vinyl releases through his label Third Man Records so when Jay Z tapped him to put together a new pressing of Magna Carta Holy Grail you had to expect they’d do something elaborate. While the release is a normal double vinyl pressing with a nice looking gatefold, the real surprise lies on the back cover — or rather, inside it. Inside of the artwork is a “postcard flexidisc” which includes a “super secret hidden track”. The only way to actually get the flexidisc though is to slice the thing open and slide it out.
Watch a demonstration in the video showing off the record below and order it through Third Man.