The MCU50N03A from Micro Commercial Components is a MOSFET with Continous Drain Current 50 A, Drain Source Resistance 5.4 to 11.5 milliohm, Drain Source Breakdown Voltage 30 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1 to 2.2 V. Tags: Surface Mount. More details for MCU50N03A can be seen below.