What is the model and standard of electrical flexible stranded wire?

Flexible Copper Stranded Wire for Electrical Engineering (Part 4): Copper Brush Wire (GB/T 12970.4-2009) was issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China and China National Standardization Administration Committee, replacing GB/T12970.4-19965438. Compared with this, the main changes are as follows: (1) Some regulations on structural and technological requirements have been deleted; Adjust some process requirements according to the structure; The requirements for manufacturing length have been revised.