After finding these tokens, I had no idea where Fond Du Lac was. I now know it’s a city in Wisconsin, and that these tokens were once used for their city lines bus service. Token size is close to a dime.
Other than the token, each necklace is made with new materials. The size of a Ball Chain necklace is 20 inches. The size of a Leather Necklace can be adjusted to as large as roughly 25 inches and down to 12 inches using the two-knot system.