The 305RK120 from RIR Power Electronics is a Silicon Controlled Rectifier with Breakover Voltage 1200 V, Breakover Current 6730 A, Gate Trigger Voltage 1.8 to 3.0 V, Gate Trigger Current 90 to 200 mA, Temperature Operating Range -40 to 125 Degree C. Tags: Stud Mount. More details for 305RK120 can be seen below.