The SHD219501 from Sensitron Semiconductor is a MOSFET with Continous Drain Current 40 to 55 A, Drain Source Resistance 0.02 ohm, Drain Source Breakdown Voltage 60 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 2.0 to 4.0 V. Tags: Surface Mount. More details for SHD219501 can be seen below.