Based on hardware listings for boards carrying this marking, the primary technical specifications include:
If the board fails to POST, check for BIOS version compatibility, especially when using 3rd Gen Intel CPUs on older 2nd Gen boards. intel desktop board 21 b6 e1 e2 specification link
Standard legacy connectivity including USB 2.0, USB 3.0, Ethernet (RJ-45), and various video outputs like VGA, DVI, or DisplayPort depending on the specific model variant. How to Find Official Specification Links Based on hardware listings for boards carrying this