The RM40N40LD from Rectron Semiconductor is a MOSFET with Continous Drain Current 42 A, Drain Source Resistance 9.5 to 16.5 milliohm, Drain Source Breakdown Voltage 40 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1 to 2.5 V. Tags: Surface Mount. More details for RM40N40LD can be seen below.