'tis a identification tag for a keychain. Recently there has been a lot of collector interest in these items. They date from the 1890s to the 1930s or later. Often a fraternal organization would sell them to members as a fund-raising operation. They would buy a bunch of the blanks, often made to represent the Eagles Lodge, etc., and a set of letter/number stamps, and make them up locally.
I've been working on collecting a set of one per state and province, but it is slow going.