Any info on Teac reel to reel cassettes?

Back in the early 80s, Teac came out with some reel to reel cassettes that was kind of unusual. The kit came with one aluminum cassette shell that took interchangable metal reels that was loaded with about 60 minutes worth of high-bias tape. The kit came with 5 of these metal reels. It was cool to watch when played in a tape deck but it was a pain to thread these tapes. I think that was why this product never gained acceptance. Does anyone have any information on this product and where I might be able to get some? Thank you for any replies.
Are you referring to the Elcaset? I think it ran at 3.5 ips.
No, I think they were refered to as Teac Open Cassettes.
I have some Teac cassettes with clear shells that contain what look like miniature reel-to-reel gold metal reels. The Teac part # is CRC-90. They are high-bias, 90 minute tapes. But, they are fully enclosed and functional cassettes, just designed to look like a mini R2R setup. Could this be to what you're referring? I can't imagine any cassette deck of that day having enough room inside the cassette well to thread a tape. That would be quite a trick. :-)