The STD12N50DM2 from STMicroelectronics is a MOSFET with Continous Drain Current 11 A, Drain Source Resistance 299 to 350 Milliohm, Drain Source Breakdown Voltage 500 V, Gate Source Voltage - 25 to 25 V, Gate Source Threshold Voltage 3 to 5 V. Tags: Surface Mount. More details for STD12N50DM2 can be seen below.