The YJJ3439KA from Yangjie Electronic Technology is a MOSFET with Continous Drain Current -0.5 to 0.5 A, Drain Source Resistance 180 to 1700 milliohm, Drain Source Breakdown Voltage -20 to 20 V, Gate Source Voltage -12 to 12 V, Gate Source Threshold Voltage -1.2 to 1.1 V. Tags: Surface Mount. More details for YJJ3439KA can be seen below.