The BT151X-800R from WeEN Semiconductors is a Silicon Controlled Rectifier with Breakover Voltage 800 V, Breakover Current 120 A, Gate Trigger Voltage 0.25 to 1 V, Gate Trigger Current 0.015 A, Temperature Operating Range -40 to 150 Degree C. Tags: Through Hole. More details for BT151X-800R can be seen below.