KT921B Material p-n-transition: Si The structure of the transistor: NPN Reserve collector power dissipation (Pc) of the transistor: 12.5 W Limiting constant voltage collector-base (Ucb): 65 V Limit constant collector-emitter voltage (Uce) transistor: 0 V Limiting constant voltage emitter-base (Ueb): 4 V Limiting continuous collector current of transistor (Ic max): 3.5 A Limiting temperature of the pn junction (Tj): 150 ° C Cutoff frequency of the current transfer ratio (Ft) of the transistor 90 MHz Collector junction capacitance (Cc): 50 pF Static current gain in the common-emitter (Hfe), min: 10