Hmmm, Beatbox. This was my first guess but the ebay-name sounded new... Thanks, fatdog.
And thank you superduper for the explanation. If I get it right, every box comes with an empty reel and two full reels (like its shown in the picture) and the idea is to not buy new cassettes but new reels for new recordings?
Maybe thats not handy or easy-to-use but If you have enough reels you need less space for music to carry with you. Because a real holds as much music like a regular cassette but need half the space... On the other hand it turns the evolution of recording media upside down. It was the bigest advantage of cassettes, that they are easy to insert. I like your point about watch makers =)
But it´s a nice gadget.