The 4N49 from ISOCOM is a RF Transistor with Gain 300 dB(DC current gain), Supply Voltage 0.7 to 1.5 V(Forward Voltage), Collector Current (Ic) 2 to 2.8 mA, Base Current (Ib) 30 uA(On State Collector Base), Power Dissipation (Pdiss) 60 to 300 mW. Tags: Through Hole. More details for 4N49 can be seen below.