The SST4391 SOT-23 3L RoHS from Linear Systems is a Junction Field Effect Transistor (JFET) with Drain Saturation Current 50 mA, Gate Source Voltage 0.7 to 1 V, Continous Drain Current 12 mA, Drain Source Breakdown Voltage 0.35 to 0.4 V, Drain Source Resistance 30 Ohm. Tags: Surface Mount. More details for SST4391 SOT-23 3L RoHS can be seen below.