The ZMM5258B with Zener Diodes LL-34 RoHS is a series of surface mount Zener Diodes manufactured by Semtech. It is specifically designed for applications that require superior power dissipation performance, absolute temperature stability, and low reverse leakage. The RoHS compliant package is made from a high temperature, low profile ceramic body and is suitable for an SMT soldering process. Each diode in the series has different Zener voltages ranging from 4.3 volts to 9.1 volts, with a 5% tolerance, and it can handle up to 1 watt power dissipation. It has a very low reverse leakage and low capacitance for excellent noise immunity. Additionally, its temperature range is -65 °C to +175 °C, making it ideal for use in extreme environments.