The Siren Board

I know this video has been here before but I haven't got the time to search right now. (Thanks Archon) What is the reason for the four bars that make it look like a Hornet?
http://www.youtube.com/watch?v=S3cY1HrJ ... re=channel

What is the reason for the four bars that make it look like a Hornet?

taking a guess, I'd think that the shallow angle of the projector walls led Federal to believe that they required those cross bars to support them, e.g. in the case of high winds. The later 500 series had a much deeper projector which probably wouldn't have needed any support.

Sounds good to me! thanks

The Cross bars were for If they wanted to code the siren the code part would go in the circle opening and closing off the air intake