The SST4391 from CALOGIC is a Junction Field Effect Transistor (JFET) with Drain Saturation Current 50 to 150 mA, Gate Source Voltage -40 V, Drain Source Resistance 30 Ohm, Gate Current 10 mA, Gate Reverse Current -200 nA. Tags: Surface Mount. More details for SST4391 can be seen below.