They do! I have the original verison of the Gemini http://www.youtube.com/watch?v=BQyPSov6n20 . They are rare to find these days because the were mostly used with Halon Supprresion systems (they do fire alarms and suppression). I have all the devices that were used with it when it was installed in a telecommunications room with HALON 1301. But, unfortunately, the manuals were not given to the owners. Kidde said they don’t have a manual, which I think is a load of crap. They told me to contact a Kidde distributor, I found one place that had one but they wanted $50 plus shipping for it. I can’t find one anywhere else.