Larger 546 KB PDF datasheet covering the 2N5400, a high-voltage PNP small-signal transistor; the size suggests a scanned or multi-part document. The name lists no manufacturer or revision. It is useful for confirming collector-emitter ratings, current gain, saturation figures and the package pinout before replacing a failed part in a driver or amplifier circuit. Open it with any PDF reader. If the scan is hard to read, the smaller 2N5400 copies in the index may give the same data more clearly.
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.