At the end of the Mexican Revolution, the peso was rendered almost worthless. Mexican craftsmen began melting down the metal to make rings, an item they could sell for more than the melted pesos were worth. In the 1940's and 50's bikers began buying these rings on their trips to the border. This was prompted by the Johnny Law being put into action, making brass knuckles highly illegal. Bikers found a quick way around it, and many began using these large silver and brass rings that would double as brass knuckles. Once associated with this powerful movement, the Mexican Souvenir (or Biker) Rings gained popularity.