This is a used audio converter from Portta that converts optical digital to coaxial + optical, and coaxial digital to optical + coaxial. It hasn't been used much, so it's relatively clean. Audio Format: Supports sampling rates of 32KHz, 44.1KHz, 48KHz, 96KHz, and 192KHz. Audio Format: LPCM2.0/5.1CH/DTS/DOLBY-AC3 etc. (Note: Not compatible with 7.1CH Dolby Digital Plus, Dolby TrueHD.)