3T22 questions

[Firematt21]

Hello all, recently found this 3T22 hiding in the wild behind a Volunteer fire Department i was told by one of their members it's current still Actively being used as a call in siren for their volunteers. While looking at the siren setup I came across a few questions on it. The Yellow box with the federal signal logo on it has the model number RC5WB just curious as to the function of this box in the system. There was also a Grey box with a federal electric logo on it with the model number 518 on it and directly across from that was a box labeled siren by pass on and off "for civil defense" I'm wondering if that might have put the siren into an attack mode of sorts. Any information or wisdom on this steup would be much appreciated!