The name 160cmq is a component code rather than a board number, so this 56.5 KB PDF, although categorised as a schematic, is most plausibly a datasheet for a common-cathode Schottky rectifier family without a voltage grade in the name. Technicians open it to read per-leg current, forward drop, leakage and pin layout when replacing a failed output rectifier. Any PDF viewer handles it. Verify the marking on the part, including the voltage suffix, before choosing a substitute.
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 @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.