The 2SK3801 from Sanken Electric is a MOSFET with Continous Drain Current -70 to 70 A, Drain Source Resistance 5 to 6 milli-ohm, Drain Source Breakdown Voltage 40 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Through Hole. More details for 2SK3801 can be seen below.