STR1550 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 500 V
• Collector-Base Voltage, max: 500 V
• Emitter-Base Voltage, max: 9 V
• Collector Current − Continuous, max: 0.5 A
• Collector Dissipation: 0.5 W
• DC Current Gain (h_fe): 100 to 300
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: SOT-23

Here is an image showing the pin diagram of this transistor.The STR1550 transistor is marked as "1550".