The BTD7521E3-0-UB-G from Cystech Electronics is a Bipolar Junction Transistor with Emitter Base Voltage 9 V, Base Emitter Saturation Voltage 0.9 to 0.74 V, Emitter Cut off Current 100 nA, Collector Base Voltage 90 V, Collector Cut off Current 10 µA. Tags: Through Hole, NPN Transistor. More details for BTD7521E3-0-UB-G can be seen below.