This part is a kind of semiconductor called 2SB1566.

Function of this product has Power Transistor (-50V/ -3A).

Manufacturers : Rohm

Image and pinout :

Some of the text within the PDF file :

Transistors 2SB1566 2SD2395 (94L-459-B350) (94L-1101-D350) 296 [ ... ]

2SB1566 PDF Datasheet Download