The SFF4392/46 from Solid State Devices is a Junction Field Effect Transistor (JFET) with Drain Saturation Current 15 to 75 mA, Gate Source Voltage -40 to -57 V, Continous Drain Current 50 mA, Drain Source Resistance 60 Ohm, Gate Reverse Current -130 to -200 nA. Tags: Through Hole. More details for SFF4392/46 can be seen below.