This is a CD 126.3 unembossed Oakman /American Insulator style insulator which was found on the Central of Georgia Railway telegraph line. They were found on the line from Fort Valley to Columbus, GA. I would like to say that I found the green one in Georgia, but I actually purchased it many years ago from Doug MacGillvary (he has access to great insulator). All of the ones found in Georgia were blue-aqua in color and had embossed domes with either "III" or "X". I probably found and traded two dozen of these into the hobby. Most of them had the "III" and there were maybe three or so with the "X" on the dome. The green one I got from Doug has a smaller dome mould mark which is hard to read. It appears to be "IV", but I can't tell for sure. It is of interest to note that there were a considerable variety of 126.3 W. Brookfield insulators on this section of line. I don't remember finding any CD 127's, but the CD 126 Western Union style was very common.

Note: These where previously known as CD 126.2 They where moved to CD 126.3 in 2019. CD 126.2 is for straight side units