The 2SK4161D from Sanken Electric is a MOSFET with Continous Drain Current 100 A, Drain Source Resistance 3.8 to 6 milli-ohm, Drain Source Breakdown Voltage 60 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 3 to 4 V. Tags: Through Hole. More details for 2SK4161D can be seen below.