2N6437 Power PNP Transistor TO-3 cc. 1988. High Collector-Emitter Sustaining Voltage , VCEO(sus) = 100 Vdc (Min), High DC Current Gain hFE = 20-80 @ IC = 10 Adc = 12 (Min) @ IC = 25 Adc, Low Collector-Emitter Saturation Voltage , VCE(sat) = 1.0 Vdc (Max) @ IC = 10 Adc, Fast Switching Times @ IC = 10 Adc , tr = 0.3 µs (Max), ts = 1.0 µs (Max), tf = 0.25 µs (Max).