I am looking for informations about this LW headset "Fernsprechgehänge FSG 5". See the label. The set came together with a headlamp, dated 1939. My first guess was Flak but the plug is equal to the LW flying helmet plugs. The headset can be weared over a steelhelmet, like the flakhelmet on the picture. It fits also on LW paratrooper helmets not on the normal M35 model. Any informations about the use of this headset are appreciated.