The 2N5551 from Diotec Semiconductor is a Bipolar Junction Transistor with Emitter Base Voltage 6 V, Base Emitter Saturation Voltage 1 V, Emitter Cut off Current 50 nA, Collector Base Voltage 160 V, Collector Cut off Current 50 nA. Tags: Through Hole, NPN Transistor. More details for 2N5551 can be seen below.