The AUIRFS8409 from Infineon Technologies is a MOSFET with Continous Drain Current 195 to 409 A, Drain Source Resistance 0.97 to 1.3 Mohms, Drain Source Breakdown Voltage 40 V, Gate Source Voltage 20 V, Gate Source Threshold Voltage 2.2 to 3.9 V. Tags: Surface Mount. More details for AUIRFS8409 can be seen below.