This product is a 4-ports SPDIF switcher, also is a digital to analog converter. You can switch any one of the four digital audio signals to the one SPDIF/Toslink audio output. At the same time, it can convert the LPCM digital audio into analog L/R audio output and headphone output. It can be used to do audio decode for the DVD, Blue-Ray DVD, PS3, X360BOX, HD Player, PC and other similar signal generator source.