The 18N20 from Goford Semiconductor is a MOSFET with Continous Drain Current 18 A, Drain Source Resistance 136 to 160 milliohm, Drain Source Breakdown Voltage 200 V, Gate Source Voltage -30 to 30 V, Gate Source Threshold Voltage 1 to 3 V. Tags: Surface Mount. More details for 18N20 can be seen below.