The BSS138BK from Nexperia is a MOSFET with Continous Drain Current 0.23 to 0.36 A, Drain Source Resistance 1000 to 6500 milliohm, Drain Source Breakdown Voltage 60 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 0.48 to 1.6 V. Tags: Surface Mount. More details for BSS138BK can be seen below.