Boardview for the K46CM laptop mainboard, revision 2.0 as indicated by the r20 tag in the name. The .fz format is a compressed boardview opened by viewers such as FlexBV, OpenBoardView or Boardviewer, and lets you click a part to see its nets and locate the matching pads on the physical board. Pair it with the schematic to find test points, follow a rail from a shorted capacitor, or check signal continuity. Make sure the revision printed on your PCB is 2.0, since part placement can shift between revisions.
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 @alischematics. Enginerys does not host this file.
How to open a .fz file
Compressed and encrypted boardview used for ASUS, ASRock and Pegatron boards.