The STD45NF75T4 from STMicroelectronics is a MOSFET with Continous Drain Current 40 A, Drain Source Resistance 18 to 24 Milliohm, Drain Source Breakdown Voltage 75 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Surface Mount. More details for STD45NF75T4 can be seen below.