I don't know if there is already a post about this but I'm going to ask it anyways.
It's kind of a dumb question, but in siren names for example a 2001, what does that "2001" stand for? I've been wondering about it for a while and couldn't get a good answer.
More for example would be: 612, T-128, Whelen WPS-2800 series, 1212's, Model 2/5.
Any kind of siren that has numbers in it's name. Does anybody know what they stand for?