This is a texture stamp that you can use to customize miniature bases. Two files are included in the package: you can print the stamp directly on your printer, or you can print the positive texture and then create a stamp using bluestuff or silicone.
To use the stamp, first cover the miniature base with a thin layer of epoxy putty (greenstuff, magic sculpt, etc). Apply some water so the stamp won’t stick. Then, press the stamp down onto the putty. You can clean up the edges either before or after the putty hardens.