The STB9NK50Z from STMicroelectronics is a MOSFET with Continous Drain Current 7.2 A, Drain Source Resistance 720 to 850 Milliohm, Drain Source Breakdown Voltage 500 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 3 to 4.5 V. Tags: Surface Mount. More details for STB9NK50Z can be seen below.