The HN4A51J from Toshiba is a Bipolar Junction Transistor with Emitter Base Voltage -5 V, Emitter Cut off Current -0.1 µA, Collector Base Voltage -120 V, Collector Cut off Current -0.1 µA, Collector Emitter Voltage -120 V. Tags: Surface Mount, PNP Transistor. More details for HN4A51J can be seen below.