Sirens

[Bronze Nurse]

Alright- I need some guidance. The MFP vehicles seem to emit two distinct siren sounds at once: one known in the states as WALE and one known as YELP. I have never heard anything like it here, but it is much more impressive than what Federal (the BIG siren manufacturer) puts out. Both sounds are of a higher pitch and cycle faster than anything I've ever heard. Does anyone know the name of the make/model of the sirens used in movie? Any help is greatly appreciated.