Component data for the 2SK3448, filed under schematics but in practice a short datasheet-style PDF of 27.6 KB. The 2SK prefix follows the Japanese JEITA scheme for N-channel field-effect transistors, so expect a MOSFET or JFET part. A technician uses such a sheet to confirm pinout, package outline, voltage and current ratings and on-resistance before fitting a replacement. Compare the marking on the original part with the document, and check that any substitute matches its package and ratings.
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.