PDF document titled DBL2018-C, 233 KB, catalogued as a schematic. The name offers only a part or document code with a C suffix and does not identify the device or maker, so open it to see whether it is a component datasheet or a circuit drawing. Such small PDFs typically hold pinouts, block diagrams and electrical ratings that help when identifying an unfamiliar IC, checking supply pins and confirming signal paths. Compare the marking on the physical part before relying on the data.
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.