The FKV550N from Sanken Electric is a MOSFET with Continous Drain Current 50 A, Drain Source Resistance 12 to 15 milli-ohm, Drain Source Breakdown Voltage 50 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 3 to 4.2 V. Tags: Through Hole. More details for FKV550N can be seen below.