This part is a kind of semiconductor called 2N5681.

Function of this product has NPN SILICON TRANSISTORS.

Manufacturers : Seme LAB

Image and pinout :

Some of the text within the PDF file :

2N5681 2N5682 MECHANICAL DATA Dimensions in mm (inches) NPN SILICON TRANSISTORS 8 .8 9 (0 .3 5 ) 9 .4 0 (0 .3 7 ) 7 .7 5 (0 .3 0 5 ) 8 .5 1 (0 .3 3 5 ) 5 .0 8 (0 .2 0 0 ) ty p . 6 .1 0 (0 .2 4 0 ) 6 .6 0 (0 .2 6 0 )  0 .6 6 (0 .0 2 6 ) 1 .1 4 (0 .0 4 5 ) 0 .8 9 m a x . (0 .0 3 5 ) 7 .7 5 (0 .3 0 5 ) 8 .5 1 (0 .3 3 5 ) d ia . 0 .7 1 (0 .0 2 8 ) 0 .8 6 (0 .0 3 4 ) ! 2 .5 4 (0 .1 0 0 ) 1 2 .7 0 (0 .5 0 0 ) m in . 4 5 ° DESCRIPTION The 2N5681 and 2N5682 are silicon expitaxial planar NPN transistors in jedec TO-39 metal case intended for use as drivers for high power transistors in general purpose, amplifier and switching circuits The complementary PNP types are the 2N5679 and 2N5680 respectively TO-39 Pin 1 – Emitter Pin 2 – Base Pin 3 – Collector ABSOLUTE MAXIMUM RATINGS [ ... ]

2N5681 PDF Datasheet Download