1. The hand-cut optical fiber switcher with 3 input and 1 output knobs can connect three playback devices with digital optical output to an audio amplifier with only a single input. Just turn the central knob to switch the device you want to play, eliminating the need for repeated insertion of cables pulling trouble 2. Imported optical fiber inner core, special micro-convex lens, digital transmission bandwidth up to 250Mb/s 3. It is suitable for the connection between DM machines with optical fiber digital terminals, power amplifiers, DVD, VCR, CD players, MD and other audio equipment 4. Digital optical input: TOSlink square x 1 5. Digital optical output: TOSlink square x 3 6. Tuhao gold body + knob and printing, no power supply required