The FK4B0420ZL from Panasonic Corporation is a MOSFET with Continous Drain Current 10.9 A, Drain Source Resistance 7 to 20 Milliohm, Drain Source Breakdown Voltage 40 V, Gate Source Voltage -10 to 20 V, Gate Source Threshold Voltage 1 to 3 V. Tags: Chip. More details for FK4B0420ZL can be seen below.