The 2N4858A from New Jersey Semiconductor is a Junction Field Effect Transistor (JFET) with Gate Source Voltage 40 V, Continous Drain Current 8.0 to 80 mA, Drain Source Breakdown Voltage 40 V, Drain Source Resistance 60 Ohm, Gate Current 50 mA. Tags: Through Hole. More details for 2N4858A can be seen below.