I brought this from my parents' house. It seems to be a magnetic health band called Aimante, a health device popular in the Showa 30s and 40s (1955-1975). Magnets are built into the expandable metal band, and it was said to be effective in promoting blood circulation and recovering from fatigue at the time. There is discoloration due to aging. Please purchase if you understand that this is a used item stored at home. Please refrain from purchasing if you are sensitive to such things.