While working on a couple of proposed mechanical siren sites today, we got a demo of Sentry's new VR series sirens. Small, but quite loud. The tones and voice are stock, but they can do custom files. This was also not their biggest model. I think it was more like their mid tier model.
https://www.youtube.com/watch?v=zZ4b3lDg9k0
https://www.youtube.com/watch?v=ONcS6SDxO8M