The KFCAB21B50L from Nuvoton Technology is a MOSFET with Continous Drain Current 15 to 39 A, Drain Source Resistance 1.05 to 4.70 milli-ohm, Drain Source Breakdown Voltage 12 V, Gate Source Voltage -8 to 8 V, Gate Source Threshold Voltage 0.35 to 1.40 V. Tags: Chip. More details for KFCAB21B50L can be seen below.