I cannot confirm that they are HDMI 2.1 compliant but have no reason to believe they are not. In fact, you will find that most of these cables use cables/wires made to this specification by one of several manufacturers. So as long as they're not using the wrong type, you should be fine. I don't need cables for 8k but I use 4k, HDR and Dolby Atmos and wanted to make sure I have cables that work and work.
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