They already answered about the copper: The difference between AP80 Copper and other colors of AP80 is the difference in exterior color and material. AP80Copper is made of pure copper material with no surface treatment, so the body is easy to oxidize and reacts with sebum and oxygen in the air while using it. You can enjoy a variety of ways to enjoy, such as aging by oxidization, and enjoying the polished surface. The spec is the same performance. Under the rain it would turn green.