The MJE340 from STMicroelectronics is a Bipolar Junction Transistor with Emitter Base Voltage 3 V, Emitter Cut off Current 0.5 mA, Collector Base Voltage 300 V, Collector Cut off Current 100 µA, Collector Emitter Voltage 300 V. Tags: Through Hole, NPN Transistor. More details for MJE340 can be seen below.