The medallion worn by the witchers of the cat school. Based on Ciris medallion from The Witcher 3 - The Wild Hunt. I make a remix from the one. 

I made a remix of alphaflight83 's model. (Witcher Medallion - Cat School by alphaflight83 - Thingiverse)

My version has a swing mechanism and a cavity  in the middle. Small items can be stored there. In my example a ring. After printing, the small pin can be inserted into the two halves. This requires some force. On the other side I glued two 2x10mm magnets. These ensure a good closure.