The S8X8ES1 from Littelfuse is a Silicon Controlled Rectifier with Breakover Voltage 800 V, Breakover Current 0.8 A, Gate Trigger Voltage 1.7 V, Gate Trigger Current 0.000005 A, Temperature Operating Range -40 to 125 Degree C. Tags: Through Hole. More details for S8X8ES1 can be seen below.