Filed in the schematic category, this 403 KB PDF concerns the 2SC3672 transistor, making it the biggest file in this batch. Following JIS conventions, 2SC numbers denote NPN bipolar devices; the name contains only the part number. A datasheet like this usually holds absolute maximum ratings, characteristic curves and package drawings. It is consulted when a transistor in this position fails, to find the pin order, verify ratings and pick a replacement of the same polarity and footprint with equal or higher limits.
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.