The 2SK3742 from Toshiba is a MOSFET with Continous Drain Current 5 A, Drain Source Resistance 2200 to 2500 milliohm, Drain Source Breakdown Voltage 900 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 4 to 5 V. Tags: Through Hole. More details for 2SK3742 can be seen below.