Marble surface: The micro-arc oxidation(MAO) is a surface treatment process, which forms a high hardness and unique marble color film, effectively improving the corrosion resistance of the metal surface New Generation 4: rovyvon a3 pro g4 comes with a USB C charging port, new USB cover, new reflector, metal button, Lock mode, and magnetic accessories, all for the best edc light (Note: USB-C cable is not included)