Bell Diameter 12.7cm 577g Manufacturing year: Unknown Metal name: Unknown How to use: Unknown Mysterious characters in the 4th photo. From the left, the number 4. To the right, is it the number .0 or the English letter J? It seems there is no function to strike the bell from the inside, so was it struck with a hard wooden hammer? Or did the internal clapper corrode and break? It is unknown. The inside is considerably corroded. As this is an old item, I will not clean it carelessly. It will be handed over as is. Please consider purchasing with your understanding. No claims, no returns, please.