The RSJ550N10 from ROHM Semiconductor is a MOSFET with Continous Drain Current -55 to 55 A, Drain Source Resistance 12 to 18.9 Milliohm, Drain Source Breakdown Voltage 100 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1 to 2.5 V. Tags: Surface Mount. More details for RSJ550N10 can be seen below.