HDMI Specification 2.1 is the most recent update of the HDMI specification featuring advanced features for the HDMI eco-system. It supports a range of Higher Video Resolutions and refresh rates including 8K60 and 4K120, Dynamic HDR, and increased bandwidth with a new 48G cable. Version 2.1 of the HDMI Specification is backward compatible with earlier versions of the Specification.manufacturer/hdmi_2_1/index.aspx