As an old American headphone company, Koss has always focused on headphone manufacturing since 1953. It is the largest headphone manufacturer in the United States, and its headphone production and sales are the first in the United States. PP, as we all know, has become a classic of parity. This KSC75 ear earphone uses the same sound generating unit as PP, and contains titanium coating on the diaphragm. Although the workmanship is simple and the appearance is not good, it is better than