Filed as a schematic, the 209CNQ135 document is almost certainly a datasheet for a high-current Schottky rectifier module in the CNQ series, where 135 points to a 135 V reverse rating. The 160 KB PDF opens in any standard viewer. Repair technicians consult such sheets for forward voltage versus current curves, junction temperature limits and outline dimensions when replacing a shorted or open diode in a power supply secondary. Confirm the part marking and package match the drawing before installing 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.