The PSMNR55-40SSH from Nexperia is a MOSFET with Continous Drain Current 500 A, Drain Source Resistance 0.47 to 1.19 milliohm, Drain Source Breakdown Voltage 40 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1 to 4.3 V. Tags: Surface Mount. More details for PSMNR55-40SSH can be seen below.