The MCR720-18io7 from Littelfuse is a Silicon Controlled Rectifier with Breakover Voltage 1800 V, Breakover Current 719 A, Gate Trigger Voltage 0.823 V, Gate Trigger Current 1633 A, Temperature Operating Range -40 to 125 Degree C. Tags: Surface Mount. More details for MCR720-18io7 can be seen below.