These HDMI Over Single Coax products send HDMI over one 75ohm Coaxial cable up to 1,500 feet, depending upon the product chosen to and HDMI device. Think of many of these products as a coax cable with HDMI connectors on both ends.
The HDMI over Single Coax devices support 1080p. By using standard and widely available 75-ohm RG-6U cables the HDMI Over Single Coax units makes extending your HDMI video and audio signals easier than using heavy & expensive copper cable & more robust than using optical fiber cable.
NOTE: There is no such thing as an HDMI to coax cable or a coax to HDMI cable as electronic products must be used to convert the 2-technologies, see why below.