The GT20J121 from Toshiba is a IGBT with Gate Emitter Voltage 25 V, Saturated Collector Emitter Voltage 1.25 to 1.80 V, DC Collector Current 20 A, Junction Temperature 150 Degree C, Gate Emitter Leakage Current 0.1 uA. More details for GT20J121 can be seen below.