The BZX584B3V9 from Micro Commercial Components is a Zener Diode with Zener Voltage 3.82 to 3.98 V, Zener Current 5 mA, Voltage Forward 0.9 V, Current 1 mA, Current Reverse Reverse Leakage Current:- 3 uA. More details for BZX584B3V9 can be seen below.