The MMBFJ309LT1G from onsemi is a Junction Field Effect Transistor (JFET) with Drain Saturation Current 12 to 30 mA, Gate Source Voltage 25 V, Forward Transfer Admittance 8.0 to 18 mS, Gate Current 10 mA, Gate Reverse Current -1.0 nA. Tags: Surface Mount. More details for MMBFJ309LT1G can be seen below.