The STD65N55F3 from STMicroelectronics is a MOSFET with Continous Drain Current 80 A, Drain Source Resistance 6.5 to 8.5 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 STD65N55F3 can be seen below.