The TSM4N80CI from Taiwan Semiconductor is a MOSFET with Continous Drain Current 4 A, Drain Source Resistance 2500 to 3000 milliohm, Drain Source Breakdown Voltage 800 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Through Hole. More details for TSM4N80CI can be seen below.