Varistors are voltage sensitive devices designed to protect circuits against transient voltage surges.
Multilayer Varistors (MLV's) are surface mount devices that utilize a ceramic multilayer-layer construction and are used to protect circuit boards in small electronics from transients generated from electrostatic discharge (ESD), inductive load switching and lightning surge remnants.
Metal Oxide Varistors (MOV's) are epoxy encapsulated zinc oxide discs with radial or axial leads. MOV's are mid-range devices used to protect small machinery, power sources and components.
Industrial MOV's are larger rigid terminal mount devices made with zinc oxide discs enclosed in epoxy polymer cases to provide complete electrical isolation. The industrial MOV's are used in high energy industrial applications.