A small 40.3 KB PDF for the 2SK2867, filed as a schematic; the modest size suggests a short datasheet or summary page. The name contains nothing but the part number. Under JEITA naming, 2SK parts are N-channel field-effect transistors. Technicians use such documents to look up pin order and key ratings before testing a suspect transistor or picking a cross-reference. Since a brief file may omit graphs or package drawings, check that the information you need is present and confirm the marking on the part.
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.