The "My Friend" knuckle-duster revolver was a defensive weapon sold on the civilian market from the late 1860s until the early 1880s. It functioned both as a revolver (this one is in .22 caliber, with a 7-shot capacity) and a blunt weapon for striking. These were made in upstate New York (in the Catskills, specifically) by a man named James Reid and his company.