The QM2421K from uPI Semiconductor is a MOSFET with Continous Drain Current -3.2 to -4 A, Drain Source Resistance 34 to 52 milli-ohm, Drain Source Breakdown Voltage -20 V, Gate Source Voltage -12 to 12 V, Gate Source Threshold Voltage -0.5 to -1.2 V. Tags: Surface Mount. More details for QM2421K can be seen below.