The IRF644 from Vishay is a MOSFET with Continous Drain Current 8.5 to 14 A, Drain Source Resistance 0.28 milliohm, Drain Source Breakdown Voltage 250 V, Gate Source Voltage 20 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Through Hole. More details for IRF644 can be seen below.