Early occupation piece I believe, with a variant pin back devise.
7th Cavalry DUI – Swivel Pin With Looped Catch, This variant of the 7th Cavalry distinctive insignia has a pin similar to that seen on Chinese insignia. The pin his housed in a thin brass sleeve, with the pin free to swivel and slide in place. The catch is looped and integral to the main pin. I believe this is Japanese made in occupation.