The Si4174DY from Vishay is a MOSFET with Continous Drain Current 17 A, Drain Source Resistance 7.8 to 13 milliohm, Drain Source Breakdown Voltage 30 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1 to 2.2 V. Tags: Surface Mount. More details for Si4174DY can be seen below.