Neuclo AlphaOne features a seamless combination of glass and metal which provides the best holding experience. The 3D curve on the back can perfectly fit into your palm. The glass went through 40 procedures under different tools. There is metal plate under the glass to keep the back cover much tougher. And the glass is tempered, making it much harder than the normal glass. The back cover of AlphaOne is not only beautiful it is also extremely durable to resist scratches and cracks.