The BC859BU from KEC Semiconductor is a Bipolar Junction Transistor with Emitter Base Voltage -5 V, Base Emitter Saturation Voltage -0.85 to -0.7 V, Collector Base Voltage -30 V, Collector Cut off Current -15 nA, Collector Emitter Breakdown Voltage -45 V. Tags: Surface Mount, PNP Transistor. More details for BC859BU can be seen below.