4K with audio optical fiber transmission. This HDMI optical fiber extender can convert HDMI high-definition signals into optical signals and transmit them 10 kilometers away, and then restore them to HDMI high-definition signals and access the display. It is compatible with HDMI devices on the market, supports 4K x 2K image resolution (up to 3840 x 2160), supports EDID & HDCP transparent transmission function, and can also support RS232 transparent transmission, with a maximum baud rate of 115200bps.