Manufactured from 2.0mm high-grade Swiss 7075 T6 aluminum, the chassis is strategically CNC machined in low-stress areas to make it as light as possible without affecting strength or rigidity. The strong aluminum backbone protects the bottom of the car from extreme conditions and abusive jumps, and is perfectly fitted to the composite chassis frame. All holes are perfectly countersunk to provide a smooth surface.The unique, revolutionary chassis design of the XB4 features XRAY Multi-Flex technology. Both the aluminum backbone and composite chassis-plate are firmly connected to create a solid framework with each piece playing a distinctive role. The aluminum chassis provides the car with stability and stiffness, while allowing torsional flex along the longitudinal axis.Note:Swiss 7075 T6 is extremely rigid aluminum material and after the hardcoating process in rare cases some small cracks may occur for example, around openings or on edges where tension in the material is highest. Those small cracks are a natural effect and have no negative impact on the performance, reliability, or lifespan of the product and as such are not considered to be a defect.Due the nature of the aluminum material and the machining process, it is normal that the chassis may be slightly bent in the longitudinal direction.