The MMBZ5249C from Micro Commercial Components is a Zener Diode with Zener Voltage 18.62 to 19.38 V, Zener Current 6.6 to 0.25 mA, Voltage Forward 1.2 V, Current Reverse Leakage Current:- 0.1 uA, Power 300 mW. More details for MMBZ5249C can be seen below.