2N5681 Bipolar Transistor

• Type: NPN
• Collector-Emitter Voltage, max: 100 V
• Collector-Base Voltage, max: 100 V
• Emitter-Base Voltage, max: 4 V
• Collector Current − Continuous, max: 1 A
• Collector Dissipation: 10 W
• DC Current Gain (h_fe): 40 to 150
• Transition Frequency, min: 30 MHz
• Operating and Storage Junction Temperature Range: -65 to +200 °C
• Package: TO-39

Here is an image showing the pin diagram of this transistor.The complementary PNP transistor to the 2N5681 is the 2N5679.You can replace the 2N5681 with the 2N5320, 2N5682 or 2SC510.