The VS-40TPS12-M3 from Vishay is a Silicon Controlled Rectifier with Breakover Voltage 1200 V, Breakover Current 500 to 600 A, Gate Trigger Voltage 1.7 to 4 V, Gate Trigger Current 40 to 270 mA, Temperature Operating Range -40 to 125 Degree C. Tags: Through Hole. More details for VS-40TPS12-M3 can be seen below.