Difference in Edwards 890 Series? Why prroduction stopped

So I know that Edwards had the 892. Which is more common than the Edwards 894’s & 895’s(regular mechanical horns) and the 896’s(speaker Strobes) which I’m guessing they were then taken over by the Edwards/EST Integrity Series.
I believe that the Integrity series is why EST doesn’t produce the 890 series(not 100% sure):
EST 732-5A-006 took over Edwards 892-1b’s
EST 765-7A-006 took over Edwards 896-001’s

Either ways. What makes the Edwards 892’s sound the way they do? What does the inside look like? (It’s easy to find out)

Sorry I meant that to 792-7A-005 replaced the 892-1b.

The 732 was just a bonus if the series(Chime Alarm).
As seen in this video: