The QS8J4 from ROHM Semiconductor is a MOSFET with Continous Drain Current -4 to 4 A, Drain Source Resistance 40 to 84 milliohm, Drain Source Breakdown Voltage -30 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage -2.5 to -1 V. Tags: Surface Mount. More details for QS8J4 can be seen below.