The 2N4091 from Central Semiconductor is a Junction Field Effect Transistor (JFET) with Drain Saturation Current 30 mA, Gate Source Voltage 40 V, Drain Source Resistance 30 Ohm, Gate Current 10 mA, Power Dissipation 1.8 W. Tags: Through Hole. More details for 2N4091 can be seen below.