The MM1Z18B is a Zener Diode SOD-123 RoHS (surface-mount, small outline diode with RoHS compliant lead-free material) manufactured by Jingdao. It is an electronic part that operates as a rectifier, regulating a circuit’s voltage by allowing current to flow in one direction only. It has a nominal voltage of 1.8 Volts and a maximum current rating of 500 mA. It is composed of a silicon PN junction encased in a SOD-123 package. The device is RoHS compliant, meaning it does not contain any harmful chemicals or materials. Its size makes it suitable for a wide range of applications in the telecommunications, automotive, medical and electronics industries.