Radio Loudspeaker LS-3, Signal Corps US Army
The LS-3 Loudspeaker was used during WWII with a variety of US Army Signal Corps receivers, such as the BC-312 and BC-348, and used on into the 1950's. Would have been used in ground installations (as opposed to use within aircraft, where headphones would likely have been the preferred method of rendering audio to the crew).
See the photo of the interior. It appears that the components may be original and untouched. We have not tested it, so selling it as-is. Measures ~8.25 inches square by ~4.5 inches deep.