2N4231A Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 40 V
• Collector-Base Voltage, max: 40 V
• Emitter-Base Voltage, max: 5 V
• Collector Current − Continuous, max: 5 A
• Collector Dissipation: 75 W
• DC Current Gain (h_fe): 25 to 100
• Transition Frequency, min: 4 MHz
• Operating and Storage Junction Temperature Range: -65 to +200 °C
• Package: TO-66

Here is an image showing the pin diagram of this transistor.The complementary PNP transistor to the 2N4231A is the 2N6312.You can replace the 2N4231A with the 2N4232A, 2N4233A, 2N5954, 2N5955 or 2N5956.