The MMBF4392LT1G from onsemi is a Junction Field Effect Transistor (JFET) with Drain Saturation Current 25 to 75 mA, Gate Source Voltage 30 V, Drain Source Resistance 60 Ohm, Gate Current 50 mA, Gate Reverse Current 1.0 nA. Tags: Surface Mount. More details for MMBF4392LT1G can be seen below.