The SSM3K339R from Toshiba is a MOSFET with Continous Drain Current 2 A, Drain Source Resistance 145 to 390 Milliohm, Drain Source Breakdown Voltage 40 V, Gate Source Voltage -12 to 12 V, Gate Source Threshold Voltage 0.85 to 1.2 V. Tags: Surface Mount. More details for SSM3K339R can be seen below.