The SCT1255SJ from SMC Diode Solutions is a Silicon Controlled Rectifier with Breakover Voltage 1200 V, Breakover Current 520 A, Gate Trigger Voltage 1.5 V, Gate Trigger Current 50 mA, Temperature Operating Range -40 to 125 Degree C. Tags: Through Hole. More details for SCT1255SJ can be seen below.