Calrad 10-42 Mic Element. What's it worth?

I posted this over on the Zed and thought I'd see if anybody here had any idea:

I have a brand new, never used Calrad 10-42 Mic Element (That is what the box says, it also says DT-50K but that is crossed out). Anybody have any idea what that is worth?

I also have an very similar, but unmarked mic element that does not have the transformer and supporting structure that the other has...it too appears to be brand new...Can anybody identify it for me and tell me what it is worth? The only marking on either is the word, "JAPAN"

Sorry the pictures are so poor.

Thanks in advance.

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I know nothing about the mic element but Calrad is still in business.

Yeah, I checked the store earlier. Searched their site, with no luck. Maybe I'll email them.

Thanks Carl.

Since it says Japan, gotta figure it's at least 25, 30 years old. Obviously a crystal element which are usually 50K to 50M.
I'm going to guess that the rest of the assembly is to match the impedance to down to 600 ohms.
The gurus will be in shortly to straighten it out.

It'll fetch much less if sold to hams in Elbonia, Moronia, Estonia or Romania.

"The gurus will be in shortly to straighten it out."
OK here we go. It's a low impedance dynamic element with a transformer to raise it to ~50K. Oddly enough that huge magnet betrays it as being a miniature speaker of the type commonly used in hi-fi headphones of the era so the transformer probably has one heck of a turns ratio. The last two look like the front and rear views of an old 60s style telephone receiver transducer (earpiece) complete with diac to protect it from voltage spikes. Japan? Eh, early Radio Shack, Bell phones were made by Western Electric in Kearney, N. J.