While true generally people know what you mean by hdmi 2.1 cable. I always look at specs and reviews before buying cables.There is no "HDMI 2.1" cable. Stating the HDMI version in the marketing is actually discouraged by HDMI since everything is backward and forward compatible. What you need to look for is an "Ultra High Speed" cable which indicates one that can carry the full 48 Gbps bandwidth.