Do you call these "cassettes"? From what I have always known these are backup storage tapes, not the standard cassette tapes you would put music on and play in your car or boom box hell these are so different they might as well be 8-Track tape. The entire internet is reporting this as a "185tb cassette tape" wow talk about a successful PR spin by Sony.
Regardless that it isn't a cassette and just a tape, that is a lot of damn storage for a backup tape or just backup period!!!