1. HDMI-compatible arc, you need to use a standard HDMI-compatible cable to output TV sound to fiber optic, coaxial, R / L ,. 3.5mm headphone jack via HDMI-compatible ARC interface (can output sound at the same time).     2. Digital to Analog Audio Converter, you can also use digital audio coaxial and optical ports as signal source input to convert to R / L, 3.5mm analog audio output.     3. Supports Remote Volume Control. From the TV When using the ARC function, you can use the remote control of the TV to control the volume. (Only support RCA (left / right) and 3.5mm output interface, turn on the CEC function of the TV.)          Keep in mind:     1. Make sure the TV has an HDMI-compatible "ARC" interface and only supports TVs with HDMI-compatible ARC function.     2. Set the audio output to PCM or LPCM before using HDMI-compatible ARC. (When the output audio is 3.5mm stereo AUX or L / R RCA, you need to set the audio source output to LPCM / PCM format ).     3. Turn on the TV's CEC function so you can control the volume. (Only supports RCAL / R and 3.5mm output interfaces.)     4. Please use standard 19 + 1 HDMI-compatible cable to support ARC function.     5. Connect different audio interface inputs, select the corresponding input switch.     Power supply interface: Micro-USB     Maximum operating current: 100mA     Working environment temperature: -10 - + 55 Celsius     Storage temperature: -20 - + 60 Celsius     Operating humidity: 10 - 90% RH (non-condensing)     Storage humidity: 5 - 95% RH (non-condensing)     Weight: 92g     Gender: Male-Male     Model Number: Audio Return Channel Adapter     Type: Coaxial Cables     Application: Multimedia     colour:Black     Material:Aluminum alloy     size:90 x 73 x 21mm          Package Contents:     1 x ARC Audio Extractor     1 x Micro-USB Power Cable     1 x 3ft SPDIF Cable     1 x EnglishManual          Only the above package content, other products are not included.     Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.