The metal plate is made from high-precision aviation aluminum, colored by anodizing process.
Good heat dissipation, fade and scratch-resistant.
The four corners and ring are made from zinc alloy, which gets a better hardness, strong anti-corrosion and shock-resistance. Four wider and thicker corners with flannel lining to avoid scratch.
The edges are processed by polishing. Four corners are polished by a machine tool and electroplated by vacuum.