There are two main methods of hacking of the lifting chain, commonly black, and electric swimming. The electrophoretic is brighter and more beautiful, but afraid of being scratched, impatient, and the environment is slightly worse. The black cooking is relatively good. The main role is to prevent rust, but the plating on the surface is also afraid of wear, so you should try to pay attention during the use process. Once the coating disappears or is damaged, there is no way to start The role of rust prevention is.