Handmade audio wire is actually a signal wire for transmitting audio signals from an audio amplifier to a loudspeaker. No matter whether the audio signals are transmitted by electrical signals or optical signals, the international classification of the signal wire used (Nice classification, International Classification of Goods and Services for Trademark Registration) is the ninth category, and the specific commodity items for application can be: cables, wires, coaxial cables, fiber optic cables, etc.