The BC818-40 from Diotec Semiconductor is a Bipolar Junction Transistor with Emitter Base Voltage 5 V, Base Emitter Saturation Voltage 1.3 V, Emitter Cut off Current 100 nA, Collector Cut off Current 0.1 to 5 µA, Collector Emitter Voltage 25 V. Tags: Surface Mount, NPN Transistor. More details for BC818-40 can be seen below.