The IRFBF20S from Vishay is a MOSFET with Continous Drain Current 1.7 A, Drain Source Resistance 8000 milliohm, Drain Source Breakdown Voltage 900 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Surface Mount. More details for IRFBF20S can be seen below.