Add an SPDIF digital audio output and standard 3.5mm audio/microphone connections to your system through USB. The ICUSBAUDIO2D External USB Sound Card lets you add an S/PDIF digital audio output and standard 3.5mm analog audio/microphone connections to your system through USB - a convenient way to bypass or replace an internal sound card without having to open the computer case. For home-theater quality sound, the USB DAC (digital-to-analog converter) offers 96KHz / 24-bit sampling rates for both playback and recording, and a 3.5mm S/PDIF port with support for Dolby Digital 5.1 surround sound (AC3) and DTS pass-through (5.1 surround sound is supported in Windows only). This versatile USB audio adapter features an integrated 3.5mm 4-position TRRS connection for your headphones or combination headset/microphone. Also a convenient external volume control for quick adjustments, a hardware EQ switch for Bass or Treble boosting, and an LED status bar to display the current sampling rate.