The STO150GK08S from Sirectifier Electronics is a Silicon Controlled Rectifier with Breakover Voltage 800 V, Breakover Current 1750 to 2150 A, Gate Trigger Voltage 1.5 to 1.6 V, Gate Trigger Current 150 to 200 mA, Temperature Operating Range -40 to 125 Degree C. Tags: Through Hole. More details for STO150GK08S can be seen below.