The KK500A from Huajing Rectifier is a Silicon Controlled Rectifier with Breakover Voltage 600 to 2500 V, Breakover Current 9000 A, Gate Trigger Voltage 0.9 to 2.5 V, Gate Trigger Current 40 to 250 mA, Temperature Operating Range -40 to 125 Degree C. Tags: Disc. More details for KK500A can be seen below.