An 80.6 KB PDF named after the 3SK265, filed under schematics but most likely a datasheet for that single device. JIS numbering uses 3SK for N-channel field-effect transistors with four terminals, typically dual-gate MOSFETs found in tuner and receiver RF amplifiers. The larger file size suggests more characteristic curves or package drawings, useful when judging a substitute. Check gate, source and drain positions here before in-circuit testing, and handle the part with antistatic care.
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.