This little thing is a curiosity as I’m not certain what it’s for. It could be for a variety of things - maybe one of those things is one of your things and this would be perfect for you. 
It’s the same diameter as a loonie coin and is about a half inch high.   Easily fits in the palm of your hand as well as a pants pocket. 
The face is painted black with a bull fighting scene etched in the same gold colour that covered the entire round box. 
It has a tiny push button lock and metal hinge.