Indexed as a schematic, a 295 KB PDF labelled 2N6426, from the JEDEC 2N series of discrete semiconductor part numbers. Nothing else is stated, so expect a datasheet with package outline, lead assignment, maximum ratings and performance curves. Technicians rely on it when replacing a failed device, confirming correct orientation on the PCB or picking a cross-reference part. It opens in any PDF reader; the RE-marked copy of the same number in this collection may differ in publisher or detail level.
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.