This is a 2 piece wall mount for a cutting board. It should fit most cutting boards. Mount the bottom piece first, then the top piece with enough room between that you can slip the cutting board up and out of the bottom piece. You will need wall anchors as the screw holes aren't spaced to hit wall studs.
Bottom piece is oriented correctly in STL file, top piece will need to be flipped 180 degrees, my apologies for not saving the STL file correctly.
The author hasn't provided the model origin yet.