Designed for use in output stage of 10W audio amplifier, voltage regulator, DC-DC converter, and relay driver. TO-251 .268(6.80) .252(6.40) .217(5.50) .205(5.20) 2 Pinning 1 = Base 2 = Collector 3 = Emitter .022(0.55) .018(0.45) .063(1.60) .055(1.40).