The SiHF18N50D from Vishay is a MOSFET with Continous Drain Current 18 A, Drain Source Resistance 230 to 280 Milliohm, Drain Source Breakdown Voltage 500 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 3 to 5 V. Tags: Through Hole. More details for SiHF18N50D can be seen below.