But that doesn't mean there is a manufacturer that makes a strobe that uses these batteries.
And isn't there a new requirement for battery life in smoke detectors? Maybe the 9 volts are the only batteries that have a long enough shelf life.
In a case like this, where the engineer asks for something that seems simple, but nobody seems to make it, I think you should stop wasting your time looking for something that might not exist.
You should throw it back to the engineer and ask him for a manufacturer and model number that he (or she) will accept. (That's probably the reason they didn't spec a model number to start with - he probably couldn't find one either.)
