The TK155U65Z from Toshiba is a MOSFET with Continous Drain Current 18 A, Drain Source Resistance 122 to 155 milliohm, Drain Source Breakdown Voltage 650 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 3 to 4 V. Tags: Surface Mount. More details for TK155U65Z can be seen below.