The FQS4903 from onsemi is a MOSFET with Continous Drain Current 0.37 A, Drain Source Resistance 4700 to 6200 milliohm, Drain Source Breakdown Voltage 500 V, Gate Source Voltage -25 to 25 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Surface Mount. More details for FQS4903 can be seen below.