The MCR3935-4HR from Digitron Semiconductors is a Silicon Controlled Rectifier with Breakover Voltage 200 V, Breakover Current 35 A, Gate Trigger Voltage 0.7 to 1.5 V, Gate Trigger Current 10 to 40 mA, Temperature Operating Range -40 to 125 Degree C. Tags: Stud Mount. More details for MCR3935-4HR can be seen below.