They look too thin and hollow to be lightning rod insulators and they don't fit any known pattern. Can you take a close-up picture of just one and post that? Maybe try the Unexpected Discoveries subforum and see if anyone has any ideas as to what they might be.
from what i can see, i agree with bill- they don't look like something that would be used for holding a lightning rod cable- too thin, and hollow to be an insulator. a good picture of one unit would be helpful
Hmmm.. they're pretty small.. looks like you have a set of 16 of them? Where did you get them? Definitely not insulators, but don't know for sure what they are.. here's a few guesses:
-paint containers from a paint box or water color set
-planters / seed starters
-some sort of laboratory testing equipment / specimen jars..
box the box for 2.00, wondering if any insulators had metal tops with it cut in fours with holes in all four pieces. Found one today the glass is attached but broke Jenny