The SiHB21N80AE from Vishay is a MOSFET with Continous Drain Current 17.4 A, Drain Source Resistance 205 to 235 Milliohm, Drain Source Breakdown Voltage 800 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Surface Mount. More details for SiHB21N80AE can be seen below.