Reference sheet for the 2N681 semiconductor, stored as a 209 KB PDF and listed in the schematic category, though a 2N designation points to a single-component datasheet. The name gives no maker, revision or package code, so confirm the lead identification and case drawing inside before soldering. Technicians use such sheets to verify ratings, read characteristic curves and choose a replacement with equal or better voltage and current limits when the original part has failed on a board.
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.