Hey guys I have discovered this little gem about 15 minutes drive from me it's a Castle Castings (?) with a blue rotor housing and red rotor located on top of a roof in the factory. It is used to warn of a gas release or explosion and it is tested on a Thursday between 1300 and 1430. Will try and get a recording.
Well, the siren's motor is the same, and the siren mount is the same, as you can see in this video of a Castle Castings siren:
https://www.youtube.com/watch?v=Oyr4wtCSFco
However, it looks to have the same port ratio on both stators and the stators look thinner that the one in the video. It may use the same motor as the Castle Castings, but it may be a different manufacturer. Anyways, we'll know after the test!