The 4N48 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) 1 to 1.4 mA, Base Current (Ib) 30 uA(On State Collector Base), Power Dissipation (Pdiss) 60 to 300 mW. Tags: Through Hole. More details for 4N48 can be seen below.