Zipped package for the Gigabyte GA-H81M-S desktop motherboard, a micro-ATX board built on the Intel H81 chipset. The name does not say what is inside, so the archive may hold a BIOS image, a schematic or service files. Unpack it and check the contents before use. If it contains a BIOS dump, back up the original SPI chip with a programmer first and confirm the image size matches the flash capacity. Also compare the board revision printed on the PCB near the slots, since Gigabyte revisions can differ in layout.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @laptopchiplevelrepair. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.