The STD14NM50NAG from STMicroelectronics is a MOSFET with Continous Drain Current 12 A, Drain Source Resistance 285 to 320 Milliohm, Drain Source Breakdown Voltage 500 V, Gate Source Voltage - 25 to 25 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Surface Mount. More details for STD14NM50NAG can be seen below.