The T4021N52TOH from Infineon Technologies is a Silicon Controlled Rectifier with Breakover Voltage 5200 V, Breakover Current 100000 A, Gate Trigger Voltage 3.5 V, Gate Trigger Current 3880 A, Temperature Operating Range -40 to 125 Degree C. Tags: Chassis Mount. More details for T4021N52TOH can be seen below.