The TIP51 from Mospec Semiconductor is a Bipolar Junction Transistor with Emitter Base Voltage 5 V, Emitter Cut off Current 1 mA, Collector Base Voltage 350 V, Collector Cut off Current 1 mA, Collector Emitter Voltage 250 V. Tags: Through Hole, NPN Transistor. More details for TIP51 can be seen below.