City of Raleigh, NC uses them for Flood Warning alarms, downstream of some of the smaller lakes south of town. 18 sets at last count by me (over 2 years ago), and the controller/amplifier cabinet must have been upgraded about 10 or 12 years ago, to use a newer model; which is now superseded by another model.
Interesting to work on if you have to swap out drivers.....anybody wanna work out of a crane basket?