This is a DXF font. It is not a .ttf or .otf system font. You must import and position each character manually. You cannot install or use it like a standard text font.
It has circular arcs and smooth geometry which standard fonts do not support for cases where standard fonts do not work right.
This set contains stencil fonts.
Each font is a category folder and each letter is a separate DXF file.
There is a separate PDF catalog for each font.