The STS321120U901AH from Eaton is a Power Diode with Reverse Current 0.01 to 0.1 µA, Reverse Voltage 12 V, Temperature operating range -55 to 150 Degree C, Reverse Breakdown Voltage 13.3 to 16 V, Total Capacitance 90 to 100 pF. Tags: Surface Mount. More details for STS321120U901AH can be seen below.