The BZX584B39 from Micro Commercial Components is a Zener Diode with Zener Voltage 38.22 to 39.78 V, Zener Current 2 mA, Voltage Forward 0.9 V, Current 0.5 mA, Current Reverse Reverse Leakage Current:- 0.1 uA. More details for BZX584B39 can be seen below.