The FDMC0310AS from onsemi is a MOSFET with Continous Drain Current 19 to 21 A, Drain Source Resistance 3.8 to 5.8 milliohm, Drain Source Breakdown Voltage 30 V, Gate Source Voltage 20 V, Gate Source Threshold Voltage 1.2 to 3 V. Tags: Surface Mount. More details for FDMC0310AS can be seen below.