tannoy raf ww2 push to signal loud speaker   loudspeaker mega rare please read

I was given this a few months back I am told its ww2 push to signal speaker I am told it was used to scramble signal to plains flying over what you see is what you get nothing more iv connect the front to a low watt stereo and there is music coming out speaker and that works fine that's as much as I no it come from a house clearance a few months back what you see is what you get 

I am told this is super rare and iv only seen one other and that's on ebay now for £2500

I am selling mine a lot cheaper   FREE  POSTAGE 

this is a nice collectors piece or a talk piece sitting in you front room ect 

There is a button on top.nothing connected to.it in side but speaker is there and fully working speaker what you see is what u get