Digital (Optical / Coaxial) to Analog (RCA Stereo L+R) Converter, Powered by USB (no Power Supply unit supplied).
If you want to use your Smart TV to play YouTube Videos and connect the sound to either a Karaoke Powered Speaker or a Karaoke Mixer then you will require this device.
Simply connect your TV's Optical or Coaxial Audio Output in to the Digital to Analog Converter Box, then you connect the stereo analog output in to the Karaoke Powered Speaker or Karaoke Mixer so you can sing-along to the music coming from the Smart TV.
If your TV has a Analog audio output RCA (Red and White) or headphone audio jack then you will not require the Digital to Analog Converter. If your Smart TV has Bluetooth then you can simply just Bluetooth Connect your TV's audio output to the Karaoke Powered Speaker and again you will not require the Digital to Analog Converter.