Thank you for contacting Mearto. This is a bronze Japanese temple bell. The patina indicates the material. It seems to be at least Edo era or earlier, based on the condition. Japanese temple bells I found on the market tend to be larger and newer and their hammer prices vary from around $200 to $400. I was able to find more bells of this size from other Buddhist countries with a patina/age closer to yours, including China and Thailand, with asking prices between $60 and $200 each.
Based on this, the Fair Market Value of your item is between $200 and $400.