The ZMM18 is a RoHS-compliant Zener diode manufactured by SLKORMICRO. It is a low-leakage, high-quality, precision threshold diode. It is used for voltage clamping, avalanche breakdown, reverse bias protection, signal rectification, and other voltage regulation applications. Its low-leakage design allows it to regulate voltages of up to 18 V, with a precision of 5% or better. It has a power rating of 250 mW and a breakdown voltage of 13.4 V. It is also UL recognized, supports RoHS, and is especially popular for low-current applications.