The 2SB1257 from New Jersey Semiconductor is a Bipolar Junction Transistor with Emitter Base Voltage -6 V, Base Emitter Saturation Voltage -2 V, Emitter Cut off Current -5 mA, Collector Base Voltage -60 V, Collector Cut off Current -10 µA. Tags: Through Hole, PNP Transistor. More details for 2SB1257 can be seen below.