The MCR218-4HR from Digitron Semiconductors is a Silicon Controlled Rectifier with Breakover Voltage 200 V, Breakover Current 100 A, Gate Trigger Voltage 1.5 V, Gate Trigger Current 10 to 25 mA, Temperature Operating Range -40 to 125 Degree C. Tags: Through Hole. More details for MCR218-4HR can be seen below.