The MCR1906-4HR from Digitron Semiconductors is a Silicon Controlled Rectifier with Breakover Voltage 200 V, Breakover Current 15 A, Gate Trigger Voltage 1.0 V, Gate Trigger Current 1.0 mA, Temperature Operating Range -65 to 100 Degree C. Tags: Through Hole. More details for MCR1906-4HR can be seen below.