Photo quizz: What's this?

Our friend in the UK, John Lindsay, sent JYOTI this picture. If you are wondering what it is, John has the answer.

"It's a hard disk in 1956...HDD with 5 MB storage!" he said. He added, "In September 1956 IBM launched the 305 RAMAC, the first computer with a hard disk drive (HDD).
The HDD weighed over a ton and stored 5 MB of data. Start appreciating your 32GB memory stick!"