The HUF75321D3ST from onsemi is a MOSFET with Continous Drain Current 20 A, Drain Source Resistance 30 to 36 milliohm, Drain Source Breakdown Voltage 55 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Surface Mount. More details for HUF75321D3ST can be seen below.