The 1N4125 from Micro Commercial Components is a Zener Diode with Zener Voltage 44.65 to 49.35 V, Zener Current 8.1 mA, Voltage Forward 1.1 V, Current Reverse Reverse Leakage Current:- 0.01 uA, Power 500 mW. More details for 1N4125 can be seen below.