The SSM3K345R from Toshiba is a MOSFET with Continous Drain Current 4 A, Drain Source Resistance 25 to 108 Milliohm, Drain Source Breakdown Voltage 20 V, Gate Source Voltage -8 to 8 V, Gate Source Threshold Voltage 0.4 to 1 V. Tags: Surface Mount. More details for SSM3K345R can be seen below.