The UN0405N2R4-PD56 from UN Semiconductor is a MOSFET with Continous Drain Current 59 A, Drain Source Resistance 2.4 to 5.2 milli-ohm, Drain Source Breakdown Voltage 40 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1 to 2.5 V. Tags: Surface Mount. More details for UN0405N2R4-PD56 can be seen below.