Yes, it's a lightning rod insulator. It would have had a metal bracket to hold it against a wall. The tie wire went through the hole and tied around the rod or cable, securing it to the cross top.
Dumb question what rings and where would they be? I have a small box of what sorta looked like shot glasses but with lips around each edge and might well also be lighting rod insulators Jenny
bills got it- probably around the turn of the century, i think the cross top's are a bit never with the ones that have only a single groove being a little older