50-60 years ago these threaded onto the bronze nozzles of a fire hydrant. Hole drilled for candle is 3/4. Get your antique American chunks of ferrous firefighting mining, foundry and pipe works history. Made in USA, maybe on an Eddy, Traverse City, or US Pipe Hydrant, not certain.
Weight each, 9 lbs, 3.5 lbs, and 3.5 lbs.