The P4B40HP2 from Shindengen America is a MOSFET with Continous Drain Current 4 A, Drain Source Resistance 1540 to 1900 milliohm, Drain Source Breakdown Voltage 400 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 3 to 4.5 V. Tags: Surface Mount. More details for P4B40HP2 can be seen below.