The IPG20N04S4-18A from Infineon Technologies is a MOSFET with Continous Drain Current 20 A, Drain Source Resistance 17.3 to 18.4 Mohms, Drain Source Breakdown Voltage 40 V, Gate Source Voltage 20 V, Gate Source Threshold Voltage 2 to 4 V. Tags: Surface Mount. More details for IPG20N04S4-18A can be seen below.