One-way transmission & Better Choice for Installation In-WallPlease note that the use of 8K fiber HDMI is directional.Sourceplug is for HDMI source devices."Display"plug is for HDMI display devices.In-wall CL3 rated cables are the most suitable choice for in-wall installations.24K gold plated joints and Aluminum alloy joints can effectively prevent the interface from breaking,and extend the service life.It contains 4 layers of shielding protection,enabling fast and stable signal transmission. Technical Upgrade HDMI2.1Eareyesail Real 8K Fiber HDMI is compliant with standard HDMI version 2.1 and is perfectly compatible with 4K HDMI 2.0/1.4. Compared to HDMI 2.0, it offers three times the transmission speed, directly from 18Gbps to 48Gbps, no more lag or frame drops when watching video with it, and supports eARC for more advanced audio signal control capabilities.Please note:If you want to implement the eARC function, you must connect the cable to the HDMI port with the eAR