Regarding Material: Copper Gold Plating Regarding Process: Electroplating Process Regarding dimensions: All measurements are done manually and there may be an error of 0.1-0.5CM. Please refer to the actual product for accuracy Special note: This product is not 100% pure gold. The internal material is copper, which has been gold-plated. People who are allergic to these two materials should purchase it carefully Product advantages: Wear resistant and non fading, excellent texture,