The 9N40 from Goford Semiconductor is a MOSFET with Continous Drain Current 9 A, Drain Source Resistance 515 to 607 milliohm, Drain Source Breakdown Voltage 400 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Surface Mount, Through Hole. More details for 9N40 can be seen below.