The 2N3958 from Solitron Devices is a Junction Field Effect Transistor (JFET) with Drain Saturation Current 0.5 to 5 nA, Gate Source Voltage -50 V, Forward Transfer Admittance 1000 to 3000 µs, Continous Drain Current 50 to 200 µA, Gate Current 50 mA. Tags: Through Hole. More details for 2N3958 can be seen below.