J-Tech Digital HDMI to HDMI ARC Adapter with CEC and Optical TOSLINK Audio Output, HDMI ARC Audio Adapter | Audio Extractor for Home Theater Application, Support 4K Support CEC Function This device will send the audio signal to AV receiver from the ARC (Audio Return Channel) enable device through optical port by using HDMI 1.4 cable. This is not a HDMI audio extractor. If you need sound from optical port, please confirm the output device support ARC, CEC and using standard HDMI 1.4 cable HDMI supports 4K, support CEC function. Support input and output up to 16 ft AWG26 HDMI standard cable length. The device has ARC switch and indicator light to let you know if ARC is disabled or enabled.