FiiO TAISHAN-D03K - S/PDIF Digital to Analog Converter.
The TAISHAN-D03K from FiiO is a simple device that converts coaxial or optical S/PDIF digital audio into a stereo analog output, perfect for multimedia components such as TVs or CD/DVD/Blu-ray players that do not feature analog output. Dual RCA phono outputs can be connected to an amplifier, while a 3.5mm mini stereo output can be used to supply signal to a WLAN wireless headphone system. (The mini stereo output is not recommended for direct connection to conventional wired headphones.)
The unit features a digital input format switch and an LED to confirm digital signal lock. Power is supplied by an included external power supply. The input will accept up to 24-bit/192 kHz resolution PCM digital audio, but Dolby Digital and DTS are not supported.
Note: Connecting regular headphones directly into the 3.5mm output is not recommended.