Short 108 KB PDF datasheet for the 2SC3601, placed in the schematic section of the index. The file name contains nothing beyond the part number, which under Japanese JIS rules indicates an NPN bipolar transistor for high-frequency circuits. Such a compact sheet usually lists ratings, key characteristics and the pinout, enough to confirm leg order with a multimeter in diode mode and to compare a replacement candidate. Any PDF reader will display it. Check package type and marking against the drawing before fitting a substitute.
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.