A：The inner and outer surfaces of the spin-on oil filter and the metal parts such as the threaded cover plate, the sealing plate and the spring need to be rust-proofed, and the surface is plated, free of rust and peeling.
A：The inner and outer surfaces of the spin-on oil filter and the metal parts such as the threaded cover plate, the sealing plate and the spring need to be rust-proofed, and the surface is plated, free of rust and peeling.