DAC Converter. It enables you to convert digital audio signal from optical and coaxial port to analog audio signal from RCA and 3.5mm jack, which solves the problem that your devices lack RCA and 3.5mm ports.Adjust Volume. Rotate the knob to adjust the volume of audio outputted from the connected device.Good Performance. With built-in high performance RTOS operating system and audio decoder chip, it supports DTS and AC-3.Wide Compatibility. It is compatible with network player, HDTV, Blu-ray Player, DVD, PS3, XBOX360, DM500S, DM800HD, etc.Plug and Play. No drivers required, easy to use.