BD159 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 350 V
• Collector-Base Voltage, max: 375 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 0.5 A
• Collector Dissipation: 20 W
• DC Current Gain (h_fe): 30 to 240
• Operating and Storage Junction Temperature Range: -65 to +150 °C
• Package: TO-126

Here is an image showing the pin diagram of this transistor.You can replace the BD159 with the 2N5657, 2N5657G, 2SC2899 or BD129.