Some speaker driver measurements...

What a great resource!
I've been looking for possible replacement mid drivers and spotted on your database the SEAS M15CH-JAM - which looks potentially to be a good replacement for the mids in a project I'm working on - however, I can't find any further info about these drivers on the Seas website or anywhere else via google - can you tell me any more about them? Were/are they a special design for a particular loudspeaker manufacturer for example?

thanks

Dan