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（1） Look at the printed words on the label and insulating skin. If there are wrong words, or the printing depth is different, or the words are vague, pay attention.
（2） Use your nails to scratch and pinch the insulation skin. The lines that can be scratched and pinched are generally inferior.
（3） Rub the insulation skin with your fingers. The skin of some low-quality insulated wires is easy to fade, especially the red wire. After rubbing, the color of the wire skin left on your fingers or the words printed on the wire skin are usually low-quality wires.
（4） When the insulating layer is ignited, it is inferior wire that can spontaneously ignite after leaving the open flame.
（5） Repeatedly bend the insulated wire. The insulation layer of low-quality wire is generally of poor material. After 3 to 4 times of bending, the insulation layer will break.
（6） According to the color of the wire core, the inferior wire is dark and has no metallic luster.
（7） Measure the outer diameter and core diameter of insulated wire. The measured values differ greatly, which is basically inferior insulated wire
（8） In terms of packaging length, it is generally 100 meters for each bundle or ring, and the allowable error in China is ± 0.5%. The length of low-quality wires is only 95 meters, or even less; Some are misleading in terms of "code" on the package.
In short, if low-quality wires are used, it will produce: 1. The wires are very hot; 2. The insulation is prone to breakdown or premature aging, resulting in electric leakage; 3. Large power consumption; 4. It is easy to cause fire and cause heavy casualties.
As the saying goes, "one cent, one cent", I hope consumers must be careful when choosing to purchase wires! Because you are not only purchasing products, but also buying a kind of safety and insurance.