Most headphones use copper wire as its material. Generally speaking the higher the purity of copper, its conductivity, the better, so the smaller the signal distortion. T PC 、OFC、LC-OFC Common now are four kinds of copper, respectively: T PC (electrolytic copper), OFC (oxygen-free copper), LC-OFC (oxygen-free copper or the crystallization of linear crystallization of oxygen-free copper) and OCC (oxygen-free copper single crystal) , and their purity is becoming more and more high-resolution for 99.5%, 99.995%, 99.995% and 99.996 more than the above. So as far as possible to buy earplugs to select high-quality copper wire headset.