I got this one a couple years ago, from the Mission in Cambodia. Made in France, by EIV, used in Cambodia and Vietnam. Note the stylised "GA" embossing on the front skirt. This stands for "GARDY", or Gardy Argnteuil, France. .There is at least one other French insulator with this marking, the GARDY G 18 busbar insulator, which is about 8 inches tall, and is an "indoor" insulator, shown [id=243850957]

This is the largest glass T-bar that I've ever seen. These were "rare" at one time, but seem to a lot more available as of recent times. This also gives me a chance to experiment with some lighting techniques, so please bear with me, until I get it right...