What are the spokes on the truck tires

The part on the wheel connecting the rim and the hub is a device for protecting the wheel rim and the spokes of the vehicle, which is characterized by a pair of circular cover plates whose diameter is close to the diameter of the wheel rim, the center of the cover plate has a hole larger than the wheel rotation shaft, a hole near the edge of the cover plate, the edge of the cover plate has an annular wheel plate, the curved surface of the wheel plate can closely fit the curved surface of the wheel rim！

Model Link：SINOTRUK HOWO TH7 460 horsepower 8X4 6.8m dump truck