The IF3601T39 from InterFET is a Junction Field Effect Transistor (JFET) with Drain Saturation Current 30 to 300 mA, Gate Source Voltage -20 V, Forward Transfer Admittance 175 mS, Gate Current 10 mA, Gate Reverse Current -0.1 nA. Tags: Through Hole. More details for IF3601T39 can be seen below.