The MMSZ4687 from Micro Commercial Components is a Zener Diode with Zener Voltage 4.3 to 4.515 V, Zener Current 50 mA(zener test current), Voltage Forward 0.95 V, Current Reverse Leakage Current:- 4 uA, Power 500 mW. More details for MMSZ4687 can be seen below.