This was the Matrix 8XV1.2 OG keyboard made by the Matrix team.
Note: This firmware only supports ISO/ANSI version (white PCB), and DOES NOT support the 8XV1.2 OG ANSI only version.
Make example for this keyboard (after setting up your build environment):
make matrix/m12og/rev2:default
See the build environment setup and the make instructions for more information. Brand new to QMK? Start with our Complete Newbs Guide.