1. Observe the appearance of the cable: a cable product with guaranteed quality, the insulation (sheath) layer is soft, tough and stretchable, the surface is smooth, and there is no roughness.
2. Look at the section of the cable: the inner copper core of a good cable is shiny, and no black magazine will appear when rubbed on white paper. The blackened core wire on the surface indicates that it has been oxidized.
3. Check the quality certificate: the cables of regular manufacturers all have the quality inspection certificate issued by the relevant departments. If there is no qualified certificate, the quality of the cable needs to be considered.
