This is a protection amulet made into a keychain with the images of the Four Heavenly Kings and Yin Yang symbol on one side of the hexagonal plate and the Chundi mirror and mantra on the back.
The Four Heavenly Gods Amulet offers one protection from legal entanglements, lawsuits, and court cases. It also protects you against bad luck from all four directions and people with ill intentions towards you.
You can also use it to transform negative energies into positive ones. To do that, simply reflect the surrounding with the mirror and then expose the mirror surface to direct sunlight for a brief moment – all the bad vibrations will be dissipated instantly.