The BSS123 from Yangjie Electronic Technology is a MOSFET with Continous Drain Current 0.2 A, Drain Source Resistance 3000 to 5500 milliohm, Drain Source Breakdown Voltage 100 V, Gate Source Voltage -20 to 20 V, Gate Source Threshold Voltage 1 to 2.5 V. Tags: Surface Mount. More details for BSS123 can be seen below.