The RM4N650LD from Rectron Semiconductor is a MOSFET with Continous Drain Current 4 A, Drain Source Resistance 1000 to 1200 milliohm, Drain Source Breakdown Voltage 650 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 2.5 to 3.5 V. Tags: Surface Mount. More details for RM4N650LD can be seen below.