Very rare Vintage NECO MD portable window mount siren light 6 V FBI Detective For Sale

I can’t find any information on this siren light. It is in its original carrying case with the newspaper packing dated August 18 1951. It temporarily mounts in the window and plugs into a 6 volt cigarette lighter. SFC16 is the serial number and MD is the model number.The light and siren are operated with controls mounted on the unit. The siren is right next to the operators ear which in my opinion is why I can’t find any information on it. I’m guessing this was a bad idea from the research and development department and canceled. Just a guess. This thing is in mint condition for possibly being 67 years old. I have tested it and it works as it should. Free shipping in lower 48 states only.