A compact 23.3 KB PDF for the 2SK2772, an N-channel FET according to the JIS 2SK naming convention, catalogued here as a schematic. In practice a file named after a discrete part is its datasheet, covering maximum ratings, electrical characteristics and package outline. Repairers consult it to verify the pin assignment before probing with a multimeter in diode mode and to compare key parameters when no exact replacement is available. Check the marking on the actual part, since the case often carries only an abbreviated code.
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.