The 4392DFN from Linear Systems is a Junction Field Effect Transistor (JFET) with Drain Saturation Current 25 mA, Gate Source Voltage 0.7 to 1 V, Forward Transfer Admittance 6 mS, Continous Drain Current 6 mA, Drain Source Breakdown Voltage 0.35 to 0.4 V. Tags: Surface Mount. More details for 4392DFN can be seen below.