Pictures for the physical shooting without any processing and modification, there may be color and shooting angle of the problem, if you have any questions in the order process, please feel free to contact me. Nuts are divided into several categories, hex nuts, loose nuts, flange nuts, four nuts, cover the mother, K mother, round nut, four claws mother, inlaid round knurled nut. The Materials are iron, steel, stainless steel, copper, copper ,,,