The MMBZ5243C from Micro Commercial Components is a Zener Diode with Zener Voltage 12.74 to 13.26 V, Zener Current 9.5 to 0.25 mA, Voltage Forward 1.2 V, Current Reverse Leakage Current:- 0.5 uA, Power 300 mW. More details for MMBZ5243C can be seen below.