The TK20J50D from Toshiba is a MOSFET with Continous Drain Current 20 A, Drain Source Resistance 220 to 270 Milliohm, Drain Source Breakdown Voltage 500 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Through Hole. More details for TK20J50D can be seen below.