This part is a kind of semiconductor called 2SK304.

Function of this product has Silicon N Channel Junction FETs.

Manufacturers : Kesailun Elctronic

Image and pinout :

Some of the text within the PDF file :

Silicon N Channel Junction FETs LH03 series of products interconvertible 2SK304 2SK304 D Symbol Applications For charge sensor, meter amplifier circuit, rheostat , chopper and gain controller for AGC, electronic switch. Electrical characteristics (Ta=25℃) SG Packag 1-Source 2-Gate 3-Drain TO-92 or TO-92s Parameter Drain to Source Voltage Gate to Drain ( Source) Voltage Gate to Source Cut-off Voltage Gate to Source Reverse Current Saturation Drain Current Forward transfer admittance Symbl BVDS VGD(S) VGS(off) IGSS IDSS |Yfs| Conditions IDS= 1uA IGS= -1uA VDS=10V IDS=1uA VDS=0VVGS=-20V VDS=10V VGS=0V VDS=10V VGS=0V f=1KHz min 30 -30 -0.3 0.6 2.5 typ max unit V V -2.5 V -1.0 nA 12 mA mS Classifications Marking Rank (LH) Marking Rank IDSS Classification (mA ) O C 0.6~1.5 Y D 1.2 [ ... ]

2SK304 PDF Datasheet Download