These were given to me shortly after I got my Novice license back in 1954. According to the person who gave them to me, they were used on the Seaboard Air Line RR in southeastern NC until sometime in the '40s when more modern equipment was installed. They were both made by The Western Union Telegraph Co. The bug in the background was also part of the gift. It was in rough shape and missing some parts so Dad sent it back to Vibroplex, had it refurbished, and gave it to me as a Christmas present. Upon dissassembly, the gap between the sounder and the wooden base was found to be caked with coal dust and soot from the steam locomotives. One AAA cell will operate it. The key is now in use in the upstairs "armchair" station.