I have know doubt, i had these headphones on and pressed the pushbutton on this Northern Electric old dispatchers phone(1971),Train Dispatcher were the proper authority that governed every movement in the Mainline operation..The,,Drop, come down from the upper crossarm, second set of open wires field side, down to every location where communication s was required on the railway, The old phones disappearred in the blink of the eye when radio towers took over in the mid 70,s...Now these are real collectables,,it brings back memories of days gone by..and simpliar place in time.....