This metal badge measures two and a half inches long and 1 3/4 inches wide. This is a scarce interesting badge that was issued during WWI.
The American Protective League was a group of volunteers who sought out anti-american activity in their neighbors, coworkers, and even family members, and reported them. It was headed up by a man named Albert Briggs, who was a Chicago advertising expert.He contributed a lot to the members, including payments, and cars so they could more easily watch the suspicious activity. The group was under the supervision of the FBI and was huge by the end of WWI, with eighty to one hundred thousand members . Many innocents were swooped up. This is a part of American history that one would want to disappear and indeed have. There is more information on this group at the following link:
The shield does not have a reddish tint like the scan.