This part is a kind of semiconductor called 2SK105.
Function of this product has N-Channel FET.
Manufacturers : NEC
Image and pinout :

Some of the text within the PDF file :
Free Datasheet http://www.datasheet4u.com/ Free Datasheet http://www.datasheet4u.com/ Free Datasheet http://www.datasheet4u.com/ [ ... ]
2SK105 PDF Datasheet Download
