The Si4488DY from Vishay is a MOSFET with Continous Drain Current 5 A, Drain Source Resistance 41 to 50 milliohm, Drain Source Breakdown Voltage 150 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 2 V. Tags: Surface Mount. More details for Si4488DY can be seen below.