The BZT52C39LP from Micro Commercial Components is a Zener Diode with Zener Voltage 37 to 41 V, Zener Current 0.5 mA, Voltage Forward 0.9 V, Current 5 mA, Current Reverse Reverse Leakage Current:- 0.1 uA. More details for BZT52C39LP can be seen below.