The IRF634S from Vishay is a MOSFET with Continous Drain Current 5.1 to 8.1 A, Drain Source Resistance 0.45 milliohm, Drain Source Breakdown Voltage 250 V, Gate Source Voltage 20 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Surface Mount. More details for IRF634S can be seen below.