These come in emerald green and in clear glass. Threadiess, dry-spot, two-piece, terminal, frog-eyes, spook insulator from Italy. Assigned as CD 698.
Be sure to check out the next two postings of some very rare and valuable insulators from Italy!!!
Thanks to Dave Dangora, for this translation from Italian, describing this insulator:
Insulator fuse holder, made up of 2 screwed-together glass parts. This type of insulator is from 1930-1940 and were very common on the walls of the houses up to the'60s, with the function of being a fuse holder for the power supply cables before they entered the homes, to protect from overloading, lightning and short circuits. Today it is difficult to find them.
The head insulator on top of the bell has screws to tighten the clamp current cables on the one hand and on the other side to make the thin wire that acts as a fuse. Inside the base there is a hole on the bracket to inject into the wall, and the same hole fastens cables that went to the counter. This insulator is as it was on its bracket, and have terminals in the original fuse.
Look for an upcoming CJotW article about these unique insulators.