The FJ4B0421ZL from Panasonic Corporation is a MOSFET with Continous Drain Current -4.1 A, Drain Source Resistance 52 to 142 Milliohm, Drain Source Breakdown Voltage -40 V, Gate Source Voltage -20 to 10 V, Gate Source Threshold Voltage -3 to -1 V. Tags: Chip. More details for FJ4B0421ZL can be seen below.