The MMIX1T550N055T2 from Littelfuse is a MOSFET with Continous Drain Current 550 A, Drain Source Resistance 1.3 milliohm, Drain Source Breakdown Voltage 55 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1.8 to 3.8 V. Tags: Surface Mount. More details for MMIX1T550N055T2 can be seen below.