This is one of the many amazing & vintage life safety videos the Youtube channel “The Alarm Museum” has helped preserve for even those outside the life safety industry to watch & enjoy, & prior to watching it I honestly didn’t think much of ESL’s 400-series: they’re nice-looking detectors for sure (I’d definitely want one in my collection, heh), & I’m sure they also work & are designed very well, but I had no idea all the ingenius features ESL included in them, including supposedly the industry’s first self-diagnostics! I have no honest clue when exactly this video was made (likely sometime in the 1990s or 2000s going by the video quality & other elements like the background music), but I figured I’d share it here so that the Forums could know it exists & hopefully also enjoy it too (& no, I don’t know why the second half is some other bit of media instead):
